Gas turbine systems and methods employing a vaporizable liquid delivery device

ABSTRACT

Systems and methods utilizing turbines, including a compressor turbine with a vaporizable liquid delivery device, are presented. A compressor turbine uses the evaporation of a vaporizable liquid at or near thermal equilibrium from the vaporizable liquid delivery device during the compression. The vapor created thereby typically carries the thermal energy discharged after the gas turbine cycle. The amount of liquid vaporized during compression, the length of time vaporization takes, the proximity to thermal equilibrium at which vaporization occurs, the amount of thermal energy recovered by recuperation, and the temperature at the inlet of the combustion chamber are generally interrelated parameters that can be controlled to increase efficiency.

RELATED APPLICATIONS

The present invention claims the benefit, under 35 U.S.C. § 119(e), of the filing of U.S. provisional patent application Ser. No. 61/016,253, entitled, “Gas Turbine Systems and Methods,” filed Dec. 21, 2007, and is incorporated herein for all purposes. The U.S. Provisional Patent Application Ser. No. 61/016,344, entitled “Piston Engine Systems and Methods,” filed Dec. 21, 2007, and U.S. patent application Ser. No. ______, filed Dec. 19, 2008, and entitled, “Piston Engine Systems and Methods,” are also herein incorporated by reference for all purposes.

TECHNICAL FIELD

The disclosed embodiments relate generally to gas turbines, and more specifically to gas turbine systems and methods employing recuperation and a vaporizable liquid delivery device.

BACKGROUND

Gas turbines are used to generate energy. A typical gas turbine is an energy producing system based on the Brayton Cycle. A typical, open-cycle, gas turbine includes (i) a compressor, which aspires ambient air and increases the air's pressure and temperature; (ii) a combustion chamber where the temperature is increased by the combustion of fuel; and (iii) an expansion turbine where the hot pressurized gas is expanded and cooled producing work. Some of the work performed by the expansion turbine may be used to drive the compressor (back work) and the remaining work may be used to turn a generator, turn a reduction gear, compress a gas, provide propulsion, or accomplish some other useful work.

Gas turbines are advantageous means of producing energy because they respond relatively quickly to load changes and have a short run-up time. The efficiency of such existing gas turbines is, however, limited and suboptimal. For example, the actual efficiency for a gas turbine based on the Brayton Cycle, with a compression ratio of ten, and using air as working gas (treated as an ideal gas) is less than forty percent (40%). Increases in the demand for energy, the cost of fossil fuels, and more stringent emissions regulations make it desirable to increase the efficiency of gas turbines.

SUMMARY

The systems and methods of the illustrative embodiments herein address shortcomings with previous gas turbines and energy production cycles. According to one illustrative embodiment, an open-cycle gas turbine system for producing power and optionally heat includes: a compressor for receiving a working gas and compressing the working gas to produce a compressed working gas; a vaporizable liquid delivery device associated with the compressor for delivering a vaporizable liquid to the working gas; a heat exchanger fluidly coupled to the compressor for receiving the compressed working gas and cooling the compressed working gas to produce a cooled, compressed working gas; a recuperator for receiving the cooled, compressed working gas from the heat exchanger and adding thermal energy to produce a heated, compressed working gas; a combustion chamber fluidly coupled to the recuperator for receiving the heated, compressed working gas from the recuperator and combusting the heated, compressed working gas to produce an exhaust gas; an expansion turbine fluidly coupled to the combustion chamber for receiving the exhaust gas and expanding the exhaust gas to develop power and to produce an expanded exhaust gas; and wherein the recuperator is fluidly coupled to the expansion turbine for receiving the expanded exhaust gas.

According to one illustrative embodiment, an open-cycle gas turbine system for producing power and optionally heat, the system includes: a compressor for receiving a working gas and compressing the working gas to produce a compressed working gas; a vaporizable liquid delivery device associated with the compressor for delivering a vaporizable liquid to the working gas; a heat exchanger fluidly coupled to the compressor for receiving the compressed working gas and cooling the compressed working gas to produce a cooled, compressed working gas; a recuperator for receiving the cooled, compressed working gas from the heat exchanger and adding thermal energy to produce a heated, compressed working gas; a combustion chamber fluidly coupled to the recuperator for receiving the heated, compressed working gas from the recuperator and combusting the heated, compressed working gas to produce an exhaust gas; an expansion turbine fluidly coupled to the combustion chamber for receiving the exhaust gas and expanding the exhaust gas to develop power and to produce an expanded exhaust gas; and wherein the recuperator is fluidly coupled to the expansion turbine for receiving the expanded exhaust gas.

According to one illustrative embodiment, a method of producing power with an open-cycle gas turbine, the method includes the steps of: compressing a working gas to produce a compressed working gas; wherein the step of compressing a working gas comprises delivering a vaporizable liquid to the working gas; cooling the compressed working gas in a heat exchanger to produce a cooled, compressed working gas; adding thermal energy in a recuperator to the cooled, compressed working gas to produce a heated, compressed working gas; combusting the heated, compressed working gas in a combustion chamber to produce an exhaust gas; expanding the exhaust gas in an expansion turbine to develop power and to produce an expanded exhaust gas; and supplying thermal energy to the recuperator from the expanded exhaust gas.

According to one illustrative embodiment, an open-cycle gas turbine system, the system includes: a compressor for receiving a working gas and compressing the working gas to produce a compressed working gas; a vaporizable liquid delivery device associated with the compressor for delivering liquid droplets to the working gas; a recuperator fluidly coupled to the compressor for receiving the compressed working gas from the compressor and delivering thermal energy to the compressed working gas to produce a heated, compressed working gas; a combustion chamber fluidly coupled to the recuperator for combusting the heated, compressed working gas to produce an exhaust gas; an expansion turbine fluidly coupled to the combustion chamber for receiving the exhaust gas and removing energy from the heat exhaust gas to produce an expanded exhaust gas; a heat exchanger fluidly coupled to the expansion turbine for receiving the expanded exhaust gas and removing thermal energy from the expanded exhaust gas to produce a cooled, expanded exhaust gas; and a conduit associated with the heat exchanger for receiving the cooled, expanded exhaust gas and delivering the cooled, expanded exhaust to the recuperator.

Referring to FIG. 33, an open-cycle gas turbine system, the system includes: a first compressor having a vaporizable liquid delivery device, the first compressor for receiving a working gas and compressing the working gas to form a compressed working gas; a recuperator fluidly coupled to the compressor, the recuperator for receiving the compressed working gas and providing thermal energy to the compressed working gas to produce a heated, compressed working gas; a first expansion turbine fluidly coupled to the recuperator for receiving the heated, compressed working gas and operable to expand the heated, compressed working gas to produce energy and a once-expanded working gas; a conduit for delivering the once-expanded working gas from the first expansion turbine to the recuperator; and a second expansion turbine fluidly coupled to the recuperator for receiving the once-expanded working gas and operable to expand the once-expanded working gas to produce energy and to produce a twice-expanded working gas.

According to one illustrative embodiment, an open-cycle gas turbine system, the system includes: a compressor having a vaporizable liquid delivery device, and wherein the compressor is operable to receive a working gas and compress the working gas to produce a compressed working gas; a recuperator fluidly coupled to the compressor for receiving the working gas and adding thermal energy to produce a once-heated, compressed working gas; a second compressor fluidly coupled to the recuperator for receiving the once-heated, compressed working gas and further compressing the once-heated, compressed working gas to produce a twice-compressed working gas; a combustion chamber fluidly coupled to the second compressor for receiving the twice-compressed working gas and combusting the twice-compressed working gas to produce an exhaust gas; a expansion turbine fluidly coupled to the combustion chamber for receiving the exhaust gas and expanding the exhaust gas to produce an expanded exhaust gas; and a conduit fluidly coupled between the recuperator and the expansion turbine for delivering the expanded working gas from the expansion turbine to the recuperator wherein the expanded working gas provides thermal energy.

According to one illustrative embodiment, an open-cycle gas turbine system, the system includes: a first compressor for receiving a working gas, the first compressor having a vaporizable liquid delivery device and operable to produce a compressed working gas; a cooler-condenser fluidly coupled to the first compressor for receiving the compressed working gas and cooling the compressed working gas to produce a condensed liquid and a cooled, compressed working gas; a conduit for delivering the condensed liquid from the cooler-condenser to the vaporizable liquid delivery device; a second compressor fluidly coupled to the cooler-condenser for receiving the cooled compressed working gas and operable to produce a twice-compressed working gas; a combustion chamber fluidly coupled to the second compressor for receiving the twice-compressed working gas and combusting the twice-compressed working gas to produce an exhaust gas; and an expansion turbine fluidly coupled to the combustion chamber for receiving the exhaust gas and operable to expand the exhaust gas to develop energy and produce an expanded exhaust gas.

According to one illustrative embodiment, an open-cycle gas turbine system, the system includes: a first compressor having a vaporizable liquid delivery device and operable to receive a working gas and to compress the working gas to produce a compressed working gas; a recuperator fluidly coupled to the first compressor for receiving the compressed working gas and operable to provide thermal energy to the working gas to produce heated, compressed working gas; a second compressor fluidly coupled to the recuperator for receiving the heated, compressed working gas from the recuperator and compressing the heated, compressed working gas to produce a twice-compressed working gas; a combustion chamber fluidly coupled to the second compressor for receiving the twice-compressed working gas and combusting the twice-compressed working gas to produce an exhaust gas; a first expansion turbine fluidly coupled to the combustion chamber for receiving the exhaust gas and operable to produce a once-expanded exhaust gas; a conduit fluidly coupled to the recuperator and the first expansion turbine, the conduit for delivering the once-expanded exhaust gas from the first expansion turbine to the recuperator; wherein the recuperator is further operable to receive thermal energy from the once-expanded exhaust gas and to produce a cooled, once-expanded exhaust gas; and a second expansion turbine fluidly coupled to the recuperator for receiving the cooled, once-expanded exhaust gas and expanding the cooled, once-expanded exhaust gas to produced a twice-expanded exhaust gas and energy.

According to one illustrative embodiment, an open-cycle gas turbine system for cooling, the system includes: a compressor having a vaporizable liquid delivery device, the compressor operable to receive a working gas and produce a compressed working gas; a recuperator fluidly coupled to the compressor for receiving the compressed working gas and providing thermal energy to the compressed working gas to produce heated, compressed working gas; a combustion chamber fluidly coupled to the recuperator for receiving the heated, compressed working gas and combusting the heated, compressed working gas to produce an exhaust gas; a first expansion turbine fluidly coupled to the combustion chamber for receiving the exhaust gas and expanding the exhaust gas to produce an expanded exhaust gas and energy; wherein the recuperator is fluidly coupled to the first expansion turbine for receiving the expanded exhaust gas from the first expansion turbine and removing thermal energy to produce a cooled, expanded exhaust gas; a cooler-condenser fluidly coupled to the recuperator for receiving the cooled, expanded exhaust gas and producing a dried working gas; a second expansion turbine fluidly coupled to the cooler-condenser for receiving the dried working gas and producing a cold working gas; and a low temperature heat exchanger fluidly coupled to the second expansion turbine for receiving the cold working gas and delivering thermal energy to the cold working gas.

According to one illustrative embodiment, an open-cycle gas turbine system, the system includes: a first compressor for receiving a working gas, the first compressor having a vaporizable liquid delivery device and operable to produce a compressed working gas; a cooler-condenser fluidly coupled to the first compressor for receiving the compressed working gas and cooling the compressed working gas to produce a condensed liquid and a cooled, compressed working gas; a conduit for delivering the condensed liquid from the cooler-condenser to the vaporizable liquid delivery device; a second compressor fluidly coupled to the cooler-condenser for receiving the cooled compressed working gas and operable to produce a twice-compressed working gas; a heating unit fluidly coupled to the second compressor for receiving the twice-compressed working gas and providing thermal energy to the twice-compressed working gas to produce an exhaust gas; and an expansion turbine fluidly coupled to the heating unit for receiving the exhaust gas and operable to expand the exhaust gas to develop energy and produce an expanded exhaust gas. Other illustrative embodiments are disclosed further below.

BRIEF DESCRIPTION OF THE FIGURES

The aforementioned features and advantages as well as additional features and advantages will be more clearly understood with reference to the detailed description below in conjunction with the drawings. Labels with text in the drawings are for illustrative purposes and are not intended to be limiting. In the drawings, like reference numerals generally refer to corresponding parts and operations throughout drawings and wherein:

FIG. 1 is a schematic diagram in cross section of the general layout of an illustrative axial turbo compressor with inter-stage injection of vaporizable liquid according to an illustrative embodiment;

FIG. 2 is a schematic diagram of an enlarged portion of the compressor stage of the illustrative axial turbo compressor shown in FIG. 1;

FIG. 3 is a schematic diagram of an illustrative compressor stage having a circumferential injection space;

FIG. 4 is a theoretical, schematic diagram of entropy (S) versus temperature (T) (an S-T diagram) for the compression of 1 m³ of air and approximately 0.062 kg of water in the illustrative axial turbo compressor of FIG. 1;

FIG. 5 is a theoretical, schematic diagram of pressure (P) versus volume (V) (a P-V diagram) for the compression of 1 m³ of air and approximately 0.062 kg of water in the illustrative axial turbo compressor of FIG. 1;

FIG. 6 is a schematic diagram of an illustrative system or arrangement for compressing a working gas and vaporizing a liquid by passing the working gas through an external tank of vaporizable liquid after one or more compression stages;

FIG. 7 is a theoretical, schematic diagram of entropy (S) versus temperature (T) (an S-T diagram) for the thermodynamic process of the illustrative system shown in FIG. 6;

FIG. 8 is a schematic diagram of an illustrative gas turbine system or arrangement where the vaporization is carried out at increased temperature and pressure;

FIG. 9 is a schematic diagram of an illustrative gas turbine system or arrangement where water is supplied to a main compressor turbine and an auxiliary compressor turbine;

FIG. 10 is a schematic diagram of an illustrative system or arrangement where the main compressor turbine aspires pre-compressed air as well as re-circulated working gas at a pressure and temperature substantially above ambient conditions;

FIG. 11 is a schematic diagram of an illustrative compressor system or arrangement;

FIG. 12 is a schematic diagram of an illustrative compressor system or arrangement;

FIG. 13 is a theoretical, schematic diagram of entropy (S) versus temperature (T) (an S-T diagram) for the thermodynamic process of the illustrative system shown in FIG. 12;

FIG. 14 is a theoretical, schematic diagram of an S-T diagram of a Brayton Cycle representing the thermodynamic process of a typical open-cycle gas turbine;

FIG. 15 is a theoretical, schematic S-T diagram of the thermodynamic process of an illustrative recuperated EVITE gas turbine cycle;

FIG. 16 is a schematic diagram of an illustrative open-cycle gas turbine system or arrangement for the combined production of heat and power (CHP) according to one illustrative embodiment;

FIG. 17 a is a theoretical, schematic S-T diagram of the thermodynamic process carried out by the illustrative system shown in FIG. 16 during maximum heat production;

FIG. 17 b is a theoretical, schematic S-T diagram of the thermodynamic process carried out by the illustrative system shown in FIG. 16 during maximum electricity production;

FIG. 17 c is a theoretical, schematic S-T diagram of the thermodynamic process carried out by the system shown in FIG. 16 during mixed heat and electricity production;

FIG. 18 is a schematic diagram of an illustrative open-cycle gas turbine system or arrangement;

FIG. 19 is a theoretical, schematic S-T diagram of the thermodynamic process of the illustrative system shown in FIG. 18;

FIG. 20 is a schematic diagram of an illustrative open-cycle gas turbine for CHP;

FIG. 21 is a theoretical, schematic S-T diagram of the thermodynamic process of the illustrative system shown in FIG. 20;

FIG. 22 is a schematic diagram of an illustrative aircraft gas turbine engine;

FIG. 23 is a theoretical, schematic S-T diagram of the thermodynamic process of the illustrative system shown in FIG. 22;

FIG. 24 is a schematic diagram of an illustrative aircraft gas turbine engine;

FIG. 25 is a theoretical S-T diagram of the thermodynamic process of the illustrative gas turbine engine shown in FIG. 24;

FIG. 26 is a schematic diagram of an illustrative open-cycle gas turbine system or arrangement with internal combustion and cleaning of the exhaust gas;

FIG. 27 is a theoretical, schematic S-T diagram of the thermodynamic process carried out by the illustrative system shown in FIG. 26;

FIG. 28 is a schematic diagram of an illustrative open-cycle gas turbine system or arrangement with external firing;

FIG. 29 a is an expanded view of the flow through the medium temperature heat exchanger in the illustrative system of FIG. 28;

FIG. 29 b is an expanded view of an alternate flow pattern through the medium temperature heat exchanger in the illustrative system of FIG. 28;

FIG. 30 is a schematic diagram of an open-cycle gas turbine system or arrangement for CHP with external firing;

FIG. 31 is a theoretical, schematic S-T diagram of the thermodynamic process carried out by the illustrative system shown in FIG. 30;

FIG. 32 is a schematic diagram of an illustrative open-cycle gas turbine system or arrangement for CHP with external firing;

FIG. 33 is a schematic diagram of an illustrative open-cycle gas turbine system or arrangement with two-staged expansion before and after the recuperator, according to one illustrative embodiment;

FIG. 34 is a theoretical, schematic S-T diagram of the thermodynamic process of the illustrative turbine system shown in FIG. 33;

FIG. 35 is a schematic diagram of an illustrative open-cycle gas turbine system or arrangement with compression before and after the recuperator;

FIG. 36 is a theoretical, schematic S-T diagram of the thermodynamic process of the illustrative gas turbine system shown in FIG. 35;

FIG. 37 is a schematic diagram of an illustrative open-cycle gas turbine system or arrangement with compression and recovery of the vaporizable liquid before the second adiabatic compression takes place;

FIG. 38 is a schematic diagram of the thermodynamic process carried out by the illustrative turbine system of FIG. 37;

FIG. 39 is a schematic diagram of an illustrative open-cycle gas turbine system or arrangement with compression before and after the recuperator and expansion before and after the recuperator;

FIG. 40 is a theoretical, schematic S-T diagram of the thermodynamic process of the illustrative turbine system shown in FIG. 39;

FIG. 41 is a schematic diagram of an illustrative open-cycle gas turbine system or arrangement for waste heat recovery according to one embodiment;

FIG. 42 is a theoretical, schematic S-T diagram of the thermodynamic process of the illustrative system in FIG. 41;

FIG. 43 is a schematic diagram of an illustrative open-cycle gas turbine system or arrangement for waste heat recovery;

FIG. 44 is a theoretical, schematic S-T diagram of the thermodynamic process of the illustrative system shown in FIG. 43;

FIG. 45 is a schematic diagram of an illustrative open-cycle gas turbine system or arrangement for waste heat recovery;

FIG. 46 is a theoretical, schematic S-T diagram of the thermodynamic process of the illustrative open-cycle gas turbine system of FIG. 45;

FIG. 47 is a schematic diagram of an illustrative open-cycle, combined piston compressor/expansion turbine system or arrangement;

FIG. 48 is a schematic diagram of an illustrative open-cycle gas turbine system or arrangement for cooling;

FIG. 49 is a schematic diagram of an illustrative open-cycle gas turbine system or arrangement with external and internal combustion;

FIG. 50 is a theoretical, schematic S-T diagram of the thermodynamic process carried out by the in the illustrative system of FIG. 49;

FIG. 51 is a schematic diagram of an illustrative open-cycle gas turbine system or arrangement using split gas streams with external and internal combustion;

FIG. 52 is a schematic diagram of an illustrative closed-cycle gas turbine system or arrangement;

FIG. 53 is a theoretical S-T diagram of the thermodynamic process carried out by the illustrative arrangement shown in FIG. 52;

FIG. 54 is a schematic diagram of an illustrative closed-cycle gas turbine system or arrangement with carbon dioxide sequestration at the lower pressure level of the system by liquefaction;

FIG. 55 is a schematic diagram of an illustrative liquefying engine which may be employed with the illustrative system shown in FIG. 54;

FIG. 56 is a schematic diagram of an illustrative closed-cycle gas turbine system or arrangement with carbon dioxide sequestration by extraction at the upper pressure level of the illustrative closed-cycle;

FIG. 57 is a schematic diagram of an illustrative closed-cycle gas turbine system or arrangement with carbon dioxide sequestration by liquefaction;

FIG. 58 is a schematic diagram of an illustrative liquefying engine which may be employed as part of the illustrative system shown in FIG. 57;

FIG. 59 is a schematic diagram of an illustrative closed-cycle gas turbine system or arrangement with carbon dioxide sequestration by extraction at the upper pressure level of the closed-cycle;

FIG. 60 is a schematic diagram of an illustrative closed-cycle gas turbine system or arrangement with CHP;

FIG. 61 is a schematic diagram of an illustrative closed-cycle gas turbine system or arrangement with CHP and carbon dioxide sequestration by liquefaction;

FIG. 62 is a schematic diagram of an illustrative closed-cycle gas turbine system or arrangement with CHP and carbon dioxide sequestration by extraction at the upper pressure level of the closed-cycle;

FIG. 63 is a schematic diagram of an illustrative closed-cycle gas turbine system or arrangement with two-staged expansion before and after the recuperator;

FIG. 64 is a schematic diagram of an illustrative aircraft gas turbine engine system operating in semi-closed cycle mode with combustion air supplied through an auxiliary compressor turbine;

FIG. 65 is a theoretical, schematic S-T diagram of the thermodynamic process of the system of FIG. 64;

FIG. 66 is a schematic diagram of an illustrative system or arrangement for waste heat recovery;

FIG. 67 is a schematic diagram of an illustrative closed-cycle combined piston compressor/expansion turbine system or arrangement;

FIG. 68 is a schematic diagram of an illustrative open-cycle gas turbine system or arrangement with compression and recovery of the vaporizable liquid before the second adiabatic compression takes place;

FIG. 69 is a theoretical, schematic S-T diagram of the thermodynamic process of the illustrative system of FIG. 68;

FIG. 70 shows an illustrative closed-cycle gas turbine with compression before and after the recuperator;

FIG. 71 is a schematic diagram of an illustrative closed-cycle gas turbine system or arrangement with compression before and after the recuperator and expansion before and after the recuperator;

FIG. 72 is a schematic diagram of an illustrative closed-cycle gas turbine system or arrangement for cooling;

FIG. 73 is a theoretical, schematic S-T diagram of the thermodynamic process of the system of FIG. 72;

FIG. 74 is a schematic diagram of an illustrative gas turbine system or arrangement combining a closed-cycle working gas cycle with an open-cycle supply of air to burn fuel in an internal combustion chamber; and

FIG. 75 shows an illustrative combined piston compressor/expansion turbine system or arrangement for carrying out a semi-closed cycle.

DETAILED DESCRIPTION

General aspects and information related to the general context of the illustrative embodiments will be presented first. Then, additional details and descriptions of illustrative systems and methods will be presented.

As used herein and as explained further below, a compressor that uses the evaporation of a vaporizable liquid at or near thermal equilibrium during the compression may be called a “compressor with evaporative inter-cooling at thermal equilibrium,” or an “EVITE compressor.” Such a compressor may be called out in other ways as well. Similarly, a gas turbine using evaporative inter-cooling at thermal equilibrium may be referred to as an “EVITE gas turbine.” The vapor created carries the thermal energy discharged after the gas turbine cycle. The amount of liquid vaporized during compression, the length of time vaporization takes, the proximity to thermal equilibrium at which vaporization occurs, the amount of thermal energy recovered by recuperation, and the temperature at the inlet of the combustion chamber are interrelated parameters that can be controlled to increase efficiency. Unless otherwise indicated, as used herein, “or” does not require mutual exclusivity.

The turbine systems and methods disclosed herein have wide application. Systems and methods disclosed herein may be used with solid fuel, for cooling, for aircraft engines, for extraction and liquefaction, waste heat recovery, exhaust gas cleaning, closed cycle engines, and other uses.

Lowering the end temperature of compressed gas tends to reduce efficiency unless a means is provided, as described herein, for heating the compressed gas after compression but before the compressed gas reaches an external source of thermal energy, such as a combustion chamber. According to one illustrative embodiment, sufficient vaporizable liquid is added to the working gas such that the gas is substantially saturated at the compression end temperature and the compression end temperature is lower than it would be without the addition of vaporizable liquid. A second compressor or recuperator (i.e., a heat exchanger for “recouping” thermal energy from exhaust) may be used to preheat the compressed working gas as described more fully below. As used herein, “substantially saturated” means a saturation of 75% or greater. At times 25% saturation may be adequate and 50% saturation may be fine—particularly at higher temperatures. 75% and higher saturation is good and 90% and higher is really good.

Vaporization during the compression process tends to increase thermodynamic efficiency when the working gas is heated at a constant pressure after compression, especially if the vaporization is carried out both quickly and near thermodynamic equilibrium. Increasing the vaporization rate merely by increasing the gas or liquid temperatures, however, tends to move the process away from thermodynamic equilibrium, and thereby reduces efficiency. To avoid or minimize a reduction in efficiency, systems and methods for providing vaporizable liquid such that the transit time of the vaporizable liquid during the compression process is sufficiently long are provided.

As used herein, “thermodynamic equilibrium” generally means the state of the working fluid, engine or whatever is considered is in a state where all partners (e.g., air plus water and steam) are in such a state that at least no important parameter (e.g. temperature, partial pressures, density, composition etc.) is changing without an expressive external actuation. Such external actuations may include compression, expansion, heating, cooling, combustion (ignition by a spark plug etc.), etc. “Thermodynamic equilibrium” may also encompass the situation where the external actuation is so slow that for a tiny external change the system follows so quickly that all working fluid changes (e.g. temperature and pressure in case of compression/expansion; or vaporization/condensation) are always settled. That is, the state change can be regarded as an infinite series of such tiny state changes. With respect to the thermodynamic equilibrium in the vaporization processes of many of the turbine systems described below, the changes occur quickly and deliberately more quickly than the compression process. The steam in the gas under compression is close to the dew point (the vapor pressure is close to the saturation pressure for the considered temperature). Because, in general terms, the more a system is away from such an equilibrium, the lower is the efficiency of the system under consideration, an important consideration is being at or near thermodynamic equilibrium.

Systems and methods using the vaporization of a liquid near thermodynamic equilibrium during the compression process to achieve substantially isentropic compression are described herein. Reference will be made to certain illustrative embodiments of the invention, examples of which are illustrated in the accompanying figures. While the invention will be described in conjunction with the illustrative embodiments, it will be understood that it is not intended to limit the invention to these particular embodiments alone. On the contrary, the invention is intended to cover alternatives, modifications and equivalents that are within the spirit and scope of the invention as defined by the appended claims.

Moreover, in the following description, numerous specific details are set forth to provide a thorough understanding of the present invention. However, it will be apparent to one of ordinary skill in the art that the invention may be practiced without these particular details. In other instances, methods, procedures, and components that are known to those of ordinary skill in the art may not be described to avoid detail not necessary.

For convenience, the International Standards Organization (ISO) standard reference conditions will be assumed for examples herein, unless otherwise specified. The ISO provides industry standard reference conditions used for comparing the power and efficiency specification of gas turbines and other engines. The ISO specifies ambient conditions of 15° C. and 60% humidity; however, it will be clear to one skilled in the art that the ambient conditions may vary according to the location and operating conditions of the gas turbine. For example, ambient air temperature can range from approximately −40° C. to approximately 40° C. or greater. The temperatures and pressures noted throughout the drawings and description are merely illustrative, unless otherwise indicated, and were calculated based on ISO standards and neglecting any mechanical inefficiencies of the various components.

Some of the illustrative embodiments described herein can be implemented in small gas turbine generators, producing between approximately 10 KWatts and 1 MWatt of energy, and medium gas turbine generators, producing between approximately 1 MWatt and 25 MWatts of energy. Some embodiments can be implemented in large gas turbine generators. Large gas turbine generators typically produce over 25 MWatts. Currently, maximum capacity gas turbines generate approximately 300 MWatts.

Throughout the description, mechanical imperfections of the various components are neglected unless otherwise noted. Thus, the given efficiencies, unless otherwise indicated, refer to the inevitable loss governed by the physical laws of thermodynamics. Taking the mechanical imperfections into account, will increase the compression end temperature and decrease efficiency, depending on the quality of the components.

A vaporizable liquid may be any liquid capable of vaporization under compression with a working gas such that the higher temperature of the working gas allows the vaporizable liquid to evaporate. In some embodiments, the vaporizable liquid may be water, ethanol, methanol, fuel, or the like, and mixtures thereof, as will be understood by one skilled in the art. Labels that appear on some of the figures are for example and it should be understood that any vaporizable liquid may be used in most embodiments. In illustrative embodiments with closed-cycle gas turbine systems, certain liquids produced by CFCs (chlorofluorocarbons) may be used as the vaporizable liquid. In some illustrative embodiments, the preferred vaporizable liquid is water. In some illustrative embodiments, the preferred vaporizable liquid is the fuel to be burned in the combustion chamber. In some embodiments, the preferred vaporizable liquid is a mixture of both fuel and water.

The amount of vaporizable liquid added to the working gas is preferably adjusted in such a manner that all of the liquid is just vaporized as compression is completed, i.e., the compressed working gas leaving the compressor is not over-saturated with vapor from the vaporizable liquid. In some illustrative embodiments, the amount of liquid vaporized is determined in such a way that at least about 80% of the thermal energy discharged into the environment (or the thermal energy transferred to the lower temperature level reserve) is carried by the vapor to be released by condensation after discharge. In gas turbines with typical upper temperatures beyond approximately 600° C., the amount of vaporizable liquid is preferably determined such the latent heat of vaporization at the discharge temperature for the amount of vaporizable liquid added to the working gas is equal to approximately 30% to 50% of the thermal energy which drives the gas turbine.

The thermal energy that drives the gas turbine may be provided by fuel or another external source of thermal energy. In some illustrative systems or arrangements, the external thermal energy is provided by a heat exchanger. In some arrangements the external thermal energy is provided by burning fuel in a combustion chamber. A combustion chamber may refer to any device that can receive gas and fuel, heat this gas by combustion of the fuel and return the gas to the system at the same, a higher, or a lower pressure. In some cases the gas received in the combustion chamber is a compressed working gas. Typical combustion chambers, such as furnaces, for gas turbines may allow maximum combustion temperatures of approximately 1450° C. because of mechanical limitations. Unless otherwise mentioned, a piston engine may be used as the combustion chamber to allow higher combustion temperatures, such as approximately 2500° C. or more. The combustion chamber can be internally or externally cooled to increase the maximum possible combustion temperature. The temperature of exhaust gas from a piston engine may be lower and this, in turn, decreases the material requirements of the first expansion turbine stages and lowers costs.

In some illustrative embodiments, the working gas may be any gas capable of combustion with the desired fuel. In some illustrative embodiments, the working gas may be nitrogen, helium, argon, or another noble gas, carbon dioxide, oxygen, an inert gas, a mixture of such gases, or the like, as will be understood by one skilled in the art. In some illustrative embodiments, the working gas may be a mixture of nitrogen and various combustion products, formed, for example, by burning natural gas or kerosene with air.

The process by which the vaporizable liquid is transformed into vapor may be referred to as evaporation or vaporization. A condensate is a vaporizable liquid that had been vapor but has been returned to the liquid state by condensation. A working gas is a gas that passes through a gas turbine in order to do work, such as producing thrust, heat, energy, or the like.

One skilled in the art will recognize that the predicted values provided by an illustrative system or method herein may vary widely based on the particular embodiment. In particular, the turbine and recuperator (i.e., a heat exchanger for “recouping” the heat from the exhaust gases) used in an illustrative embodiment will affect the temperatures predicted. The temperatures predicted are subject to the thermal and mechanical tolerances of the materials in a particular physical embodiment. In a preferred embodiment, components with maximum thermal and mechanical tolerances are used to allow for maximum temperatures and maximum efficiency. Turbines, including compressor turbines and expansion turbines, may be multi-stage or single stage turbines.

As will be appreciated by one skilled in the art, the degree of recuperation depends on the temperature of the working gas as the working gas leaves the compressor (the compression end temperature). Lower compression end temperatures increase the effectiveness of the recuperator given the same exhaust gas temperature.

I. Compressors

An isentropic compression process holds the entropy of a working gas constant, while raising the working gas' temperature and pressure. The Brayton Cycle assumes perfectly isentropic compression, but real compressors irreversibly increase the entropy of the working gas in an adiabatic process that is not isentropic. The increase in entropy can be reduced by vaporizing a liquid near thermodynamic equilibrium during the compression process. A compressor, as used herein, is a device for compressing a working gas, including gas-vapor mixtures or exhaust gases, and includes pumps, compressor turbines, reciprocating compressors, piston compressors, rotary vane or screw compressors, and devices and combinations capable of compressing a working gas. In some embodiments, a particular type of compressor, such as a compressor turbine, may be preferred. A piston compressor may be used herein to include a screw compressor, rotary vane compressor, and the like.

In some illustrative embodiments the working gas is mixed with a vaporizable liquid, so that the gas and the liquid are compressed in the compressor together thereby producing a gas-vapor mixture, reducing the temperature increase caused by the compression process, and substantially holding the entropy of the working gas constant. In some embodiments the vaporizable liquid evaporates near thermodynamic equilibrium. Compressors include parts, such as turbine blades or impellers, which may be eroded by the impact of fast moving liquid or particles in the working gas. In some embodiments the vaporizable liquid evaporates in a manner such that the liquid does not contact the compressor parts after the liquid is introduced to the working gas. In some illustrative embodiments, a working gas, such as nitrogen, is compressed for use in a device or chemical process, such as an engine. In some illustrative embodiments, the compressor is driven by an external engine, such as an electric motor, a gas turbine, or a diesel engine. In some embodiments the compressor is driven by energy produced by the working gas.

A. Evaporative Cooling Methods for Compressors

Unlike the illustrative embodiments disclosed herein, techniques such as inlet fogging, or misting, attempt to increase energy output from gas turbines by lowering the intake temperature of aspired air in hot, but dry, environments. Typically, inlet fogging only adds as much vapor as can saturate the air at the intake temperature so that no vaporization occurs during compression and the liquid does not impact compressor parts. Lowering the end temperature of compressed gas tends to reduce efficiency, unless a means is provided, as described herein, for heating the compressed gas after compression but before the compressed gas reaches an external source of thermal energy, such as a combustion chamber. According to illustrative embodiments described herein, sufficient vaporizable liquid is added to the working gas such that the gas is substantially saturated at the compression end temperature and the compression end temperature is lowered compared to the compression end temperature without the addition of vaporizable liquid. A second compressor or recuperator (i.e., a heat exchanger) may be used to preheat the compressed working gas as described more fully below.

Vaporization during the compression process tends to increase thermodynamic efficiency when the working gas is heated at a constant pressure after compression—especially if the vaporization is carried out both quickly and near thermodynamic equilibrium. Merely, increasing the vaporization rate by increasing the gas or liquid temperatures, however, tends to move the process away from thermodynamic equilibrium, and thereby reduces efficiency. In some embodiments droplet size or the flow rate of the working gas is reduced. In some embodiments, the working gas temperature and pressure are increased as part of the introduction and evaporation of the vaporizable liquid.

1. Initial Injection of Vaporizable Liquid

One method of supplying vaporizable liquid to a compressor, while maintaining the liquid-working gas mixture at or near thermodynamic equilibrium in order to achieve substantially isentropic compression is to supply the entire amount of vaporizable liquid before compression. For example, the vaporizable liquid may be supplied to the compressor with the working gas by spraying droplets through injection nozzles. Medium to high-pressure pumps may supply pressurized liquid to injection nozzles which spray small droplets of vaporizable liquid into the working gas before compression begins.

In some cases, including for fast running axial turbines, the vaporizable liquid droplets must be small enough to avoid damaging the blades or other parts of the compressor by impact. For a turbine compressor in particular, the impact of vaporizable liquid on the fast moving impeller, or—after acceleration by the impeller—other parts of the turbo compressor, may erode the compressor parts. For radial turbines, even high droplet content and comparably large droplets do not cause damage. In general, the vaporizable liquid should be injected into the working gas in the form of droplets that are as small as possible, in order to increase the surface area of vaporizable liquid in contact with the working gas. In one illustrative embodiment, the droplets of vaporizable liquid may be less than 5 μm in diameter.

Compression raises the temperature of the working gas causing substantially continuous evaporation of the vaporizable liquid throughout the compression process. The evaporation process in turn uses thermal energy added by the compression process. Thus, the temperature of the working gas is lower temperature than the working gas would be without evaporation and raising of the dew point of the gas-vapor mixture. In other words, the compression energy is used to vaporize the liquid.

The amount of vaporizable liquid supplied may be enough to absorb the thermal energy from the compression process. The amount of liquid vaporized is determined in such a way that at least about 80% of the thermal energy discharged into the environment (or the thermal energy transferred to the lower temperature level reserve) is carried by the vapor to be released by condensation after discharge. In gas turbines with typical upper temperatures beyond approximately 600° C., the amount of vaporizable liquid is preferably determined such that the latent heat of condensation at the discharge temperature (or for closed-cycle systems the lower thermal reserve temperature) for the amount of vaporizable liquid added to the working gas is equal to approximately 30% to 50% of the thermal energy that drives the gas turbine. The total amount of vaporizable liquid may be supplied at a rate between approximately 7% to approximately 20% of the aspiration rate of the working gas by mass. For example, in a 30 MW gas turbine burning natural gas and having an air mass flow of approximately 50 kg/s, the injection rate of water, which is used as the vaporizable liquid, is preferably between approximately 3.9 kg/s (7.8% of air mass flow) and 6.5 kg/s (13% of air mass flow) corresponding to a condensation power of 9 MW to 15 MW. The thermal energy that drives the gas turbine may be provided by fuel or another source of thermal energy, such as a heat exchanger.

In some illustrative embodiments the compressed working gas may be between approximately 50% saturated and completely (100%) saturated with vapor after compression. The vaporizable liquid may be pressurized and injected at a higher temperature than that of the working gas, so that the vapor pressure of the vaporizable liquid exceeds that of the working gas pressure causing the droplets to “explode” into more and smaller droplets. In some illustrative embodiments, the partial pressure of the vapor may not be more than around 20% of the partial pressure of the working gas without the added vapor. In some illustrative embodiments, the vaporizable liquid may be pre-heated, before injection, to a temperature in the range between the compression end temperature without injection and the decreased compression end temperature of the saturated working gas after injection and vaporization.

In some illustrative embodiments, the temperature difference between the working gas and the vaporizable liquid is minimized. When minimizing the temperature difference between the working gas and the vaporizable liquid, the vapor pressure of the liquid is still generally far below the working gas pressure. For example, the vapor pressure of water at 120° C. is around 2 bar, while the pressure of the working gas may be approximately 10 bar at 120° C. or, in closed cycles, even higher.

The amount of vaporizable liquid provided preferably is such that, at the end of compression, the working gas is substantially saturated by the vapor produced and no droplets are present after compression, (i.e., all liquid supplied has been vaporized). The substantially saturated working gas may, for example, be nearly saturated at less than 100% saturation. The substantially saturated working gas may, for example, be somewhat sub-saturated, or at least approximately 50% saturated. The nearer the working gas is to complete saturation throughout the compression process, the higher the efficiency. The working gas is preferably at least 50% saturated during the compression process.

A surplus of vaporizable liquid may be injected before or during compression if the compressor is of a type unlikely to be damaged by the liquid. For example, a radial or diagonal compressor is unlikely to be damaged. The surplus is then removed after compression and re-circulated for re-injection. The surplus may be removed after compression by a gas-liquid separator. The device that introduces the vaporizable liquid to the working gas before or during compression may be referred to as a vaporizable liquid delivery device.

2. Inter-Stage Injection of Vaporizable Liquid Droplets

A method of supplying vaporizable liquid according to some illustrative embodiments includes supplying the vaporizable liquid to a compressor in stages to help facilitate substantially isentropic compression. The liquid is supplied such that the flow through the compressor is at or near thermodynamic equilibrium. In some illustrative embodiments, the compressor is a multi-stage axial turbine compressor. In some illustrative embodiments, radial or diagonal turbines may be employed in conjunction with or instead of axial turbines.

Referring to FIG. 1, the general layout of an axial turbine compressor 100 with inter-stage liquid injection, e.g., water, according to an illustrative embodiment is shown. The axial turbine compressor 100 receives a working gas 101 at an inlet 103 and compresses the working gas 101 before the working gas 101 exits at outlet 105. The turbo compressor 100 may include multiple stages such as the six stages 102 a, 102 b, 102 c, 102 d, 102 e, and 102 f each having an impeller (or impeller blades) 104 a, 104 b, 104 c, 104 d, 104 e, and 104 f; a diffuser or stator 106 a, 106 b, 106 c, 106 d, 106 e, and 106 f, and an injection channel 108 a, 108 b, 108 c, 108 d, 108 e, and 108 f. In some embodiments, the impellers 104 are mounted on the same shaft 110 and rotated quickly at the same revolution speed. In some embodiments, the impellers 104 are mounted on a plurality of shafts (not shown). In some embodiments each compressor stage includes an injection channel adjacent to its respective diffuser, such that the working gas flows through the diffuser before entering the injection channel. In some embodiments, the injection channels are provided with injectors, such as injection nozzles or the like.

In some illustrative embodiments, each one of the injection channels 108 a, 108 b, 108 c, 108 d, 108 e, and 108 f may contain a set of injection nozzles (or injects) 112 a, 112 b, 112 c, 112 d, 112 e, and 112 f, respectively, that together function as the vaporizable liquid delivery device. In some illustrative embodiments, the volume of injection channels 108 is such that the transit time for the vaporizable liquid droplets to cross each injection channel 108 is at least 20 ms over the typical flow rate of the working gas. In some embodiments, the volume of the injection channels 108 is set so that the transit time is between approximately 50 ms and 500 ms. In some embodiments, the volume of the injection channels 108 is set so that the transit time is between approximately 0.1 s and 1 second. In general longer transit times are preferable to allow the vaporizable liquid to completely vaporize. The volume of an injection space, such as injection channels 108, may, however, be constrained in some applications. In such an embodiment, a circumferential injection space may be used, as described in more detail below with respect to FIG. 3. The use of the circumferential injection space can significantly increase transit time without significantly increasing the length of the turbine casing and, hence, the turbine 100.

In some illustrative embodiments each set of injection nozzles 112 may be arranged in a ring configuration. Each set of injection nozzles 112 may alternatively be arranged in a grid of injection nozzles. The injectors may inject the liquid into the injection channels 108 so as to distribute the liquid droplets evenly in the working gas flow. The liquid injection may also take place in the diffusers 106. In this case, the injection channels 108 may be partly or completely omitted.

In some illustrative embodiments, the injector 112 injects and atomizes vaporizable fluid in droplets of a diameter of less than 5 μm so that substantially all of the droplets evaporate in the slow moving working gas, e.g., air. Only enough vaporizable liquid to absorb the thermal energy from the temperature increase due to compression is added at each stage 102. The vaporizable liquid for injection at each stage may be pre-heated to a temperature in the range between the temperature at which the working gas is aspired by the impeller and the temperature at which the further compressed gas enters the injection area.

The evaporation of the injected liquid droplets cools the working gas. Because cooler working gas requires less work to compress at a given pressure ratio, the overall efficiency of the axial turbine compressor 100 is increased by the evaporative cooling at thermal equilibrium after each diffuser 106. The thermodynamic properties of the gas-vapor mixture allow for a much higher expansion ratio in the axial turbine compressor 100 leading to a substantially lower exhaust temperature. In addition, the higher mass flow increases the power output from the axial turbine compressor 100.

At each injection channel 108, the vaporizable liquid is completely evaporated such that the droplets do not damage the impeller blades 104. The cooled working gas, with the completely vaporized fluid, enters each subsequent impeller, diffuser, and injector, and the process repeats as described above at the next stage 102. Vaporizable liquid can be added in quantities up to the saturation point of the compressed working gas.

In some illustrative embodiments, the temperature increase during the compression process is controlled, as desired. For example, vaporizable liquid may be injected only in the first four stages 102 a-d. Then compression in the subsequent two stages 102 e and 102 f may be completed without liquid vaporization which thereby leads to a higher end temperature. Alternatively, the injection nozzles 112 may be throttled and inject only a part of the liquid required to substantially saturate the working gas. Consequently, each stage 102 raises the temperature of the working gas more than with evaporation of the complete amount of liquid because there is less evaporative cooling at each stage. Injecting vaporizable liquid between only some of the stages 102 requires less mechanical compression power because the corresponding thermodynamic process is nearer equilibrium.

Referring now to FIG. 2, an enlarged portion of a compressor stage 102, according to an illustrative embodiment is shown. When the shaft 110 is rotated, the impeller 104 aspires working gas and accelerates the working gas. In some illustrative embodiments, compression may occur at the impeller 104. In this case the working gas accelerated by the impeller 104 enters the diffuser 106 at an elevated temperature and is decelerated in the diffuser 106. Consequently, the pressure and temperature rises. The subsequent liquid injection by injectors then lowers the temperature while maintaining the pressure.

The fast moving working gas 101 slows in the diffuser 106 and flows into the injection channel 108 at a moderate speed (e.g., approximately 50 m/s in one illustrative embodiment). Because of the acceleration of the working gas 101, and the subsequent slowing in the diffuser 106, both the temperature and pressure rise. Consequently, the temperature of the compressed working gas 101 flowing into the injection channel 108 is significantly higher than the temperature at which the working gas was aspired by the impeller 104. To cool the working gas 101, the injection nozzles 112 at the entrance of the injection channel 108 inject the vaporizable liquid into the warmed working gas. Because the speed of the working gas in channel 108 is relatively low, the droplets have enough time to vaporize. For example, droplets of approximately 5 μm in diameter may require a transit time of approximately 50 milliseconds (ms) to approximately 100 ms to vaporize. Thus, for a working gas velocity of approximately 50 m/s, the injection channel 108, or injection space, should be between approximately 2.5 and 5 meters long. The circumferential injection space described below creates a suitably long flow path for the working gas in a relatively compact area.

The energy required for evaporation is taken from the warm working gas which, in turn, cools down. The amount of vaporizable liquid injected is controlled in such a way that at the end of the injection channel 108 no droplets or nearly no droplets are present. The temperature decrease caused by the vaporization process may also be adjusted by varying the amount of vaporizable liquid that is injected.

The pressurized and cooled working gas then leaves the injection channel 108 a and, hence, the first compressor stage 102 a, and is aspired by the impeller 104 b of the next stage 102 b. Similar to the process in the first stage 102 a, in the second stage 102 b, the impeller 104 b accelerates the working gas 101 (now mixed with vaporized liquid) and the diffuser 106 b slows the working gas down, further increasing its pressure and temperature. When entering the injection channel 108 b, the injection nozzles 112 b inject and atomize the vaporizable liquid for evaporation.

This process may be carried out in each subsequent stage, e.g., stages 102 c-f. Finally, the compressed working gas 101 leaves the axial turbo compressor 100 with substantially increased pressure but a minor temperature increase. The temperature increase is dependent on the vapor saturation property of the injected liquid. The compressed working gas leaving the final stage 102 f through outlet 105 may contain no more vapor than the maximum vapor density at the dew point of the working gas. In some illustrative embodiments, the compressed working gas 101 is no more than approximately 1% oversaturated. The amount of vaporized liquid provided during compression defines the cooling power of the injection process, and this amount defines the minimum compression end temperature proximate outlet 105.

Referring now to FIG. 3, an alternative compressor stage 300 is presented. The compressor stage 300 includes a circumferential injection space 302. Sub-sonic conditions are assumed for the description of the flow described with respect to FIG. 3. The circumferential injection space 302 allows a working gas with a relatively large velocity component in the circumferential direction to travel a longer distance than the injection channel 108 of FIG. 1. In compressor stage 300, the impeller 104 with blades 304 aspires the working gas entering the turbine stage 300, accelerates the working gas, and alters the working gas direction. For example, if the impeller blades 304 move in the direction of the arrow V1 for the cross section shown, and the working gas enters the turbine stage 300 in the direction of the arrow V2, the working gas leaves the impeller 104 in the direction of the arrow V3. The blades 306 of the diffuser 106 slow down the working gas and, consequently, increase its pressure. The blades 306 also reverse the circumferential flow so that the working gas leaves the diffuser 106 in the direction of the arrow V4. Because the velocity has larger circumferential component V4 c than longitudinal component V41, the working gas travels a relatively longer distance in the circumferential direction within the injection space (or circumferential chamber) 302. Injection nozzles 308 inject liquid to be vaporized into the circumferential chamber 302. Increasing the transit time from the diffuser 106 to the outlets or nozzles 308 to the subsequent compressor stage may allow substantially all of the injected liquid to vaporize.

The working gas may rotate up to several times in the circumferential chamber 302 before the working gas enters the next compressor stage. In some illustrative embodiments, the chamber 302 may be structured in the form of a worm gearbox (not shown) to avoid mixing the working gas freshly supplied by the diffuser 106 with working gas which has already been circulating in the chamber 302 and is more saturated with vapor. The working gas, which may be a gas-vapor mixture, is supplied to the following compressor stage through the curved outlets 308 which produce the desired flow vector V2 for the working gas. The blades 308 change the direction of the working gas flow from the helical flow path within the chamber 302 (where they can perform several revolutions around the longitudinal axis of the turbine to establish a sufficiently along path way, i.e. time, for vaporization) in such a way that the final direction is appropriate for the nozzle of the subsequent compressor stage or to leave the compressor, if the last stage has been reached already.

By using a circumferential injection space 302 instead of a straight injection channel, e.g., channel 108 in FIG. 1, the passage and, hence, the transit time can be increased by a factor as large as ten or more. In some cases the transit time may be increased by a factor of 100. This means that the transit time can be raised from a typical value below 1 ms to 100 ms or even more. This allows complete vaporization of the injected liquid even if the final vapor content is near saturation.

Referring now to FIGS. 4 and 5 theoretical, schematic diagrams of entropy (S) versus temperature (T) (an S-T diagram) and pressure (P) versus volume (V) (a P-V diagram), respectively, for the compression of 1 m³ of air and approximately 0.062 kg of water in an axial turbo compressor according to the illustrative embodiment of FIG. 1 are presented. The compression process described with respect to FIGS. 1 and 2 using liquid injection after every compression stage 102 approximates a pure isentropic process as indicated in FIGS. 4 and 5. The reference letters in FIGS. 4 and 5 correspond to respective stages of the compressor turbine shown in FIG. 1. After every injection, the subsequent compression is substantially isentropic, hence the temperature rises, but the entropy remains virtually unchanged as shown in FIG. 4. The injection of vaporizable liquid, and evaporation in a non-saturated space, lowers the temperature but increases entropy.

The values shown in FIGS. 4 and 5 were calculated for 1 m³ of air with 100% humidity at 15° C. and 1013 mbar at the beginning of compression. The compression ratio used was 8, so the final pressure after compression was approximately 8.104 bar. The compression end temperature at outlet 105 was calculated to be approximately 91° C. The amount of vaporized water in the gas-vapor mixture was approximately 0.075 kg, of which 0.062 kg was injected and vaporized and 0.013 kg of vapor was already present in the ambient air at 100% humidity. The mechanical work used for compression was approximately 256 kJ. The entropy increase was approximately 0.021 kJ/K, corresponding to an irreversible loss of mechanical energy of approximately 6.1 kJ at ambient conditions. In other words, only 2.4% of the mechanical work required was lost due to entropy increase. Thus, inter-stage injection of vaporizable liquid near equilibrium and during compression enables substantially isentropic compression with a thermodynamic efficiency of approximately 97.6%.

Pre-heating the vaporizable liquid for injection to a temperature between the predicted compression end temperature without injection and the predicted temperature of the saturated gas-vapor mixture after injection and vaporization (i.e., between approximately 114° C. and approximately 91° C. for compressor stage 6 in FIG. 1) may lower the loss of mechanical energy due to the irreversible vaporization process at each stage. For example, for a gas turbine arrangement using the compression process described above with reference to FIGS. 1-5, with a combustion chamber that raises the temperature of the working gas (air-steam mixture) by approximately 500K (i.e., provides approximately 800 kJ of thermal energy), then the loss of mechanical energy due to the irreversibility of the compression with injection of water is only about 0.7%. This is negligible compared to the benefits of the thermodynamic cycle according to the illustrative embodiments described, wherein the condensation of the vaporized liquid near ambient temperature increases the overall efficiency of the engine.

3. Continuous Supply of Vaporizable Liquid

Some illustrative embodiments supply the vaporizable liquid continuously during compression (by injection, for example) and carry out the compression under virtually continuous vaporization of the liquid, i.e., the liquid vaporizes with the temperature increase due to the compression increases, and the dew point rises. The vaporizable liquid may be continuously injected, for example, by simple nozzles, and travel with the working gas through at least one stage in the compressor. If both the temperature and the pressure of the working gas are sufficiently high, then vaporization is rapid. Consequently, this strategy is especially suited for a turbine with exhaust gas re-circulation at increased temperature and pressure, as shown in FIGS. 8 and 9.

4. Inter-Stage Gas-Liquid Mixing in External Tanks

Referring now to FIG. 6 a system 601 or arrangement for compressing a working gas and vaporizing a liquid by passing the working gas through an external tank of vaporizable liquid after one or more compression stages is presented. In the case where axial turbines are used for the compressor, the working gas is compressed in a plurality of compressor stages before being delivered to an external tank of vaporizable liquid. FIG. 7 is a theoretical S-T diagram of the thermodynamic process carried out by the system 601 shown in FIG. 6.

The external tanks 663, 667, 671 hold significantly more vaporizable liquid than the working gas can absorb by evaporation. The volume of the external tanks 663, 667, 671 may be adjusted such that transit time through each tank is between approximately 0.1 and 1 seconds. For example, for a 10 MW gas turbine with four compressor stages, each with a compression ratio of 2:1 and a vaporization tank, the volume of the first tank 663 may be approximately 6 m³, while the third tank 671 may have a volume of approximately 1 m³. In some cases, the external tanks may be formed as ring chambers encircling the turbine.

The temperature of the vaporizable liquid in each external tanks 663, 667, 671 may be within approximately 20K of the temperature at which the working gas leaves that respective tank. Compression with vaporization near thermodynamic equilibrium can be arranged by passing a working gas through an external tank of vaporizable liquid after one or more compression stages.

In some embodiments, a radial compressor 660 aspires a working gas and compresses the working gas to a first compression end temperature and pressure. The working gas may be supplied to a first external tank 663 of vaporizable liquid at a first tank temperature between the intake temperature and the first compression end temperature. In some embodiments, the working gas passes through the tank 663 in between about 0.1 and 1 seconds. In some embodiments saturating the working gas with the vaporizable liquid may involve repeatedly spraying large quantities of vaporizable liquid through or into the working gas, passing the working gas through the vaporizable liquid, using waterfall “curtains,” or other methods for saturating the working gas with vapor from the vaporizable liquid to optimize evaporative cooling at or near equilibrium. In the tank 663, the working gas is cooled by evaporation to a temperature approximately equal to the tank temperature. After mixing the vaporizable liquid with the working gas, the working gas, which is then a substantially saturated gas-vapor mixture, is discharged from the tank 663. If non-vaporized liquid remains mixed with the working gas non-vaporized liquid may be removed, for example by a centrifugal separator (not shown).

A second radial compressor 665 then compresses the working gas (gas-vapor mixture) to a second compression end temperature and pressure before supplying it, via a conduit 666 or other suitable means, to a second external tank 667 for mixing with vaporizable liquid at a temperature between the first tank temperature and the second compression end temperature. Again mixing and evaporative cooling until saturation at the second tank temperature is carried out before discharge. Any non-vaporized liquid may be removed before the working gas (gas-vapor mixture) is compressed in the third radial compressor 669 to a third temperature and pressure. The compressed working gas (gas-vapor mixture) is again mixed with vaporizable liquid and cooled by additional evaporation in a third external tank 671 at a third tank temperature between the second tank temperature and the third compression end temperature.

In embodiments for Combined Heat and Power (CHP) generation, thermal energy may be provided to external users through the heat exchanger 673. In embodiments where a fixed amount of thermal energy is provided to external consumers, the third external tank 671 may be omitted in some situations. When an additional expansion is carried out between the recuperator 674 (i.e., a heat exchanger) and the exhaust conduit 678, as described with reference to FIGS. 33 and 39, the third vaporization tank 671 may also be omitted.

In some cases, the temperature of the vaporizable liquid in each respective tanks 663, 667, 671 is near the working gas temperature upon leaving each respective tank. Thus, most of the thermal energy required for vaporization in the tanks comes from the compressed and heated working gas entering each tank and only a minor part from pre-heating the vaporizable liquid before supplying the working gas to each vaporization tank. The working gas is preferably saturated with vapor upon leaving each tank. The corresponding working gas (gas-vapor mixture) temperature is a function of the temperature of the working gas after compression, the liquid temperature in each tank and the saturation characteristics (condensing line) of the vaporizable liquid.

5. Vaporization at Increased Pressure and Temperature

In closed and mixed cycle gas turbine systems or arrangements, the compressor may aspire a working gas at a temperature and pressure above ambient, which correspondingly increases the vaporization rate. The vaporizable liquid may be supplied to the compressor turbine(s) at substantially higher pressures and temperatures than ambient conditions. The working gas may include exhaust gas and vapor from a previous gas turbine cycle.

Referring to FIG. 8, an illustrative compressor turbine 880, which part of a turbine system or arrangement 801, aspires re-circulated exhaust gas at an increased base pressure and temperature. At this temperature level, the vaporization rate is higher allowing vaporization within shorter transit times between the stages of the compressor turbine 880. Hence, the supplied vaporizable liquid 805, e.g., water, evaporates rapidly and maintains the working gas at a more or less constant temperature, even when the working gas (gas-vapor mixture) leaves the compressor turbine 880 at an increased pressure.

The compressed working gas (gas-vapor) passes through the recuperator 881 (i.e., a heat exchanger) where the working gas is heated at a substantially constant pressure. Afterwards the working gas enters the combustion chamber 882.

The auxiliary compressor turbine 883 aspires air and provides sufficient oxygen to combustion chamber 882 through conduit 807 to burn the fuel in the combustion chamber (or combustor) 882. The auxiliary compressor turbine 883 compresses air to substantially the same pressure as the compressed working gas (gas-vapor mixture) at the combustion chamber 882. In some embodiments, the compressed air may be pre-heated by an optional recuperator 885 before being supplied to the combustion chamber 882 and mixed with fuel.

The fuel (not shown) provided to the combustion chamber 882 is ignited, burns and increases the temperature of the gases in the chamber. The gases in the combustion chamber may include the working gas (gas-vapor mixture) from the compressor turbine 880, the air or air/fuel mixture from the auxiliary compressor turbine 883, and the combustion products from the combustion of the fuel. The hot working gas mixture is then delivered through conduit 809 to the expansion turbine (or expander) 887 and expanded in the expansion turbine 887 to the base pressure of the system 801. The expanded but still hot working gas passes along the conduit 888 and through the recuperator 881/885 to heat the compressed working gas from the compressor turbine 880 and optionally the compressed air from the auxiliary compressor turbine 883.

After the recuperator 881/885, the working gas flow is split into a larger part, which is re-circulated through the conduit 889 to the compressor turbine 880, and a lesser part which is supplied through the conduit 890 to an auxiliary expansion turbine (auxiliary expander) 891. This expansion turbine 891 expands the still hot and humid working gas to ambient pressure and a corresponding temperature.

Instead of supplying all of the vaporizable liquid to the main compressor at 805 and compressing air alone in the auxiliary compressor 803, the supply of vaporizable liquid can be split among these two compressors.

Referring to FIG. 9, a gas turbine system or arrangement 901 where a liquid 921, e.g., water, is supplied to a main compressor turbine 900 and a liquid 923 is supplied to a second auxiliary compressor turbine 904. The main compressor turbine 900 aspires re-circulated working gas at a base pressure and temperature. Liquid is supplied and the compression is carried out, leading to a more or less stable compression end temperature. A first auxiliary compressor turbine 902 aspires fresh air through the inlet 903 and compresses air before the air is supplied to the second auxiliary compressor turbine 904. The pre-compressed and dry air is further compressed in the second auxiliary compressor turbine 904 under continuous vaporization of liquid 923, e.g., water, which is supplied externally. Both, the working gas streams from the main compressor turbine 900 and the second auxiliary compressor turbine 904 pass separately through the recuperator 925 where they are heated. Because of the very low oxygen content of the re-circulated working gas from the main compressor turbine 900, a separate supply of the compressed aspired working gas (air/steam mixture), which contains the oxygen for combustion, from the second auxiliary compressor turbine 904 is preferably provided to cause a stable ignition and combustion of the fuel in the combustion chamber 905.

By burning the fuel in the combustion chamber 905, the working gas temperature increases while maintaining the pressure. The expansion turbine 906 expands the hot working gas to the base pressure. The expanded working gas is supplied through the conduit 907 to the recuperator 925 where the expanded working gas heats, both, the compressed re-circulated working gas from the main compressor turbine 900 and the aspired working gas from the second auxiliary compressor turbine 904. Consequently, the working gas temperature decreases. Most of the working gas is re-circulated through the re-circulation conduit 908 to the main compressor turbine 900, while a smaller part is supplied through the conduit 909 to the auxiliary expansion turbine 910. The expansions turbine 910 expands the still pressurized working gas down to ambient pressure, before the working gas is discharged into the environment through the exhaust 911.

The vaporizable liquid 921, 923 may be supplied to the compressor turbines 900 and 904 at substantially higher pressures and temperatures than ambient conditions, and the steam produced is drained from the system 901 through the auxiliary expansion turbine 910.

The vaporizable liquid is vaporized in a working gas at a higher temperature than the low temperature reserve of the engine. In general, the low temperature reserve is at ambient temperature; but the low temperature reserve may be higher for systems or arrangements with Combined Heat and Power (CHP) generation or lower for cryogenic devices. In addition, vaporization begins when the working gas is at a pressure above the pressure of the low temperature reserve. Parameters of system 901 are configured such that the initial density of the vapor produced is close enough to the saturation density that at the end of the compression process the working gas is at least 50% saturated with vapor. If isothermal compression at a given temperature would cause the vapor to condense, the temperature of the working gas may be increased during the compression and vaporization process. Even in such a case, the temperature increase is lower than in the case of pure working gas compression without liquid vaporization.

By re-circulating exhaust gas 907 which is already highly saturated (i.e., approximately 50% or more) with steam at the re-circulation pressure and temperature, the subsequent vaporization at main compressor turbine 900 of the newly supplied liquid 921 occurs near thermodynamic equilibrium. The nearer to thermodynamic equilibrium that the vaporization process is, the smaller the entropy increase during vaporization. Thus, by increasing the pressure of the working gas mixture, the entropy increase is limited. By increasing the temperature along with the pressure, the vaporization rate is also raised.

Additionally, to avoid a secondary cooling circuit with a cooling tower, it is possible to use an auxiliary expansion turbine 910 instead. It is also possible to supply pre-compressed fresh air or air/steam mixture to the main compressor turbine. FIG. 10 shows a system 1001 or arrangement where the main compressor turbine 1022 aspires pre-compressed air as well as re-circulated working gas.

Referring to FIG. 10, a first auxiliary compressor turbine 1020 aspires fresh air at ambient conditions and compresses the air adiabatically. The second auxiliary compressor turbine 1021 (which may be, in fact, mounted in the same casing and simply constituting a later compressor stage of the first auxiliary compressor turbine) compresses the pre-compressed air further under continuous vaporization of a liquid 1003 while maintaining the temperature. The main compressor turbine 1022 aspires the pre-compressed air/steam mixture from the second compressor turbine 1021 and re-circulated working gas from conduit 1028 and compresses them further under continuous vaporization of a liquid 1005, e.g., water, while maintaining the temperature.

It must be noted that the main compressor turbine 1022 may also increase the temperature if such an amount of steam is produced that saturation is reached or even surpassed. After the main compressor turbine 1022, the compressed working gas is delivered by conduit 1007 to a recuperator 1023 and passes through the recuperator 1023 (i.e., a heat exchanger) where the working gas is heated while maintaining its pressure. The working gas is then delivered by conduit 1009 to a combustion chamber 1024. Then fuel is then burned in the combustion chamber 1024. Alternatively, the working gas temperature may be increased in another way, such as an external thermal source through a heat exchanger.

The main expansion turbine 1025 receives the working gas from the combustion chamber 1024 and expands the hot and highly pressurized (e.g., 1200° C. and 125 bar) working gas. After the main expansion turbine 1025, the working gas flow is split into a minor flow in conduit 1011, which is supplied to an auxiliary expansion turbine 1026, and a major flow in conduit 1027, or through the re-circulation conduit 1027. The auxiliary expansion turbine 1026 expands the working gas to an ambient pressure and exhaust temperature.

A major part of the working gas is supplied through the re-circulation conduit 1027 to the recuperator 1023 to raise the temperature of the compressed working gas from the main compressor turbine 1022. At the same time, the recuperator 1023 cools down the working gas from conduit 1027, and the working gas is supplied to the main compressor turbine 1022 through the conduit 1028.

By using system 1001 or arrangement 1001, the liquid vaporized in the auxiliary compressor turbine 1021 as well as the main compressor turbine 1022 is drained from the system 1001 through the auxiliary expansion turbine 1026 into the environment. Therefore, a secondary cooling circuit with a cooling tower is not needed.

B. Compressor-Turbine Combination

Referring now to FIG. 11, an illustrative system 1101, or compressor combination, for producing a compressed fluid, e.g., air, using evaporative cooling instead of oil cooling is presented. The system 1101 includes a compressor 1160, a condenser 1161, and a pressure tank 1162. The compressor 1160 receives the fluid, e.g., air, at intake 1103. After compression, the fluid (e.g., air/vapor mixture) is delivered by conduit 1105 to the condenser 1161 and cooled in the condenser 1161 to remove the condensed liquid. The system 1101 thereby generates dry compressed gas for consumption. The dry, compressed gas is delivered by conduit 1107 to the pressure tank 1162. A plurality of delivery conduits 1163 may be used to deliver the dry, compressed gas.

The compressor 1160 aspires fluid, e.g., air, and compresses the fluid under continuous evaporation of vaporizable liquid 1109. Droplets of vaporizable liquid 1109 may be injected in the course of compression as shown so that they are compressed along with the air as described above. Alternatively, the vaporizable liquid may be introduced at inlet 1103. The vaporizable liquid may also be supplied via external tanks as described above. The external tanks effectively replace external intercoolers. Vaporizable liquid may also be supplied at a raised temperature and pressure as described above.

For compression ratios of around ten, the compression end temperature at conduit 1105 is approximately 100° C., and the compressed air is substantially saturated with steam after compression. Then, the fluid (air/vapor mixture) is cooled in the condenser 1161 to remove the condensed liquid 1111 from the fluid before the dried fluid, e.g., air, is transferred to the pressure tank 1162 for storage and buffering. The vaporized liquid is removed in the condenser 1161 by further cooling the fluid, e.g., air, which takes advantage of the higher heat transfer rate for condensation. The dried, compressed fluid may then be delivered through delivery conduits 1163 for external use.

Even for extraordinarily dry air, for example with less than 15% humidity, after compression under continuous evaporation of droplets, the saturation condition is reached. For example, with the pressure compression ratio of ten and a desert-like humidity of 15%, the dew point is above ambient temperature because ten times more air and, consequently, more steam is compressed into the same volume. In this example, the humidity of the compressed mixture would reach approximately 150% at ambient temperature. By vaporizing water in the course of compression in the compressor turbine 1161 and using the cooler-condenser 1161 to remove vapor from and cool the compressed air, instead of using oil injection or the like for cooling, the power consumed by the system 1101 is less than oil-based system.

C. Device Comprising a Compressor Turbine with a Power Engine

Referring now to FIG. 12, another illustrative system 1201 for producing a compressed fluid, e.g., air, is presented. FIG. 13 shows a theoretical, schematic diagram of entropy (S) versus temperature (T) (an S-T diagram) for the thermodynamic process the system 1201, arrangement, shown in FIG. 12. A compressor and an engine to drive the compressor are formed as a unit comprising a compressor turbine 1280, a recuperator 1281, a combustion chamber or heat exchanger 1282, an expansion turbine 1283, a cooler-condenser 1284, and a pressurized storage tank 1285.

The compressor turbine 1280 aspires a working gas, e.g., air, at inlet 1203 and compresses the working gas with evaporation of vaporizable liquid 1205. In some embodiments, the working gas is air and the vaporizable liquid is water. The vaporizable liquid may be injected in the course of compression as shown so that they are compressed along with the air and completely evaporate as described more fully above. Alternatively, the liquid may be introduced at inlet 1203. In some arrangements, the compression process includes vaporizing a liquid by passing the working gas through an external tank of vaporizable liquid after one or more compression stages(s) as described above. The compression process may alternatively include aspiring a re-circulated working gas at a temperature and pressure above ambient and supplying the vaporizable liquid to the compressor turbine(s) at substantially higher pressures and temperatures than ambient conditions. The compressed working gas, e.g., air, is saturated after compression.

The compressed working gas (mixture) then enters the recuperator 1281 (i.e., a heat exchanger) where the working gas is heated by the hot exhaust gases from the expansion turbine 1283. The compressed working gas (mixture) leaves the recuperator 1281 through conduit 1207 and is delivered to combustion chamber or heat exchanger 1282. In combustion chamber or heat exchanger 1282, additional thermal energy is added to the working gas. In some arrangements, the working gas enters the combustion chamber 1282 where fuel is burned, creating exhaust gas. The hot working gas leaves the combustion chamber 1282 (or heat exchanger) and is delivered by conduit 1209 to the expansion turbine where the working gas is expanded to an intermediate pressure above ambient pressure.

In some arrangements the combustion chamber 1282 is replaced by a heat exchanger to further heat the compressed working gas mixture delivered from the recuperator 1281. For example, a heat exchanger may supply the additional thermal energy from an external heat source if a combustible fuel cannot be used or if the compressed gas to be produced cannot include the products of combustion. The use of a heat exchanger allows for the use of virtually any gas as the working gas as long as the gas does not have an unwanted reaction with the vaporizable liquid. For example, the working gas may be pure nitrogen. Alternatively, as non-limiting example, the working gas may be pure oxygen and may combine with pure hydrogen in the combustion chamber 1282 to produce water, which may be removed at the cooler condenser 1284.

The expanded working gas (exhaust gas) is supplied through a delivery conduit 1211 to the recuperator 1281 where exhaust gas heats the compressed working gas (e.g., air and vapor mixture) from the compressor turbine 1280. Then, the exhaust gas is delivered by conduit 1213 to a cooler-condenser to remove the condensed water from the gas before the dried gas is transferred by conduit 1215 to the pressure tank 1285 for storage and buffering. The water condensed in the cooler-condenser 1284 can be re-circulated through the conduit 1287 to the compressor turbine 1280 to be vaporized again. Additional liquid or all the liquid may also be supplied through liquid inlet 1217. The compressed exhaust gas delivered to the pressure tank 1285 constitutes the compressed gas for user applications. In some embodiments, the exhaust gas can be further cleaned before entering the pressure tank 1285 or before subsequent use. The compressed gas may be delivered from tank 1285 to consumers, or end users, by a plurality of conduits 1286.

In some embodiments, part of the compressed working gas (e.g., air/steam mixture) may be extracted from the compressor turbine 1280 when the desired pressure for the pressure tank 1285 is reached (i.e., the pressure after expansion in the expansion turbine 1283) and supplied directly to the cooler-condenser 1284 for drying. The remaining aspired air/steam mixture is further compressed and passed through the recuperator 1281, the combustion chamber or heat exchanger 1282, the expansion turbine 1283, and the recuperator 1281 before remaining working gas is merged with the extracted part that directly entered the cooler-condenser 1284 from the compressor 1280.

II. Gas Turbines Compressing a Working Gas with a Vaporizable Liquid

A. Open-Cycle Gas Turbines

Referring to FIG. 14, a thermodynamic process is presented that may be carried out with a typical open-cycle gas turbine. First, a gas turbine engine takes in, or aspires, a working gas, which is typically air. For convenience, the working gas is assumed to be air; however, it will be clear to one skilled in the art that the working gas may be any gas which burns with fuel in a combustion chamber. Then, the aspired air is compressed. This is shown in FIG. 14 by the state change A→B. This substantially isentropic compression causes the temperature and pressure to rise. Then, fuel is added to the working gas and burned. Burning the fuel with the working gas further increases the temperature of the working gas while maintaining the pressure, as shown by the state change B→C in FIG. 14. The hot working gas is then isentropically expanded down to ambient pressure, as indicated in FIG. 14 by the state change C→D. Finally, the expanded but still hot working gas is discharged by the gas turbine into the environment where the gas is further cooled down by mixing with the ambient air. This step is depicted in FIG. 14 by state change D→A. One skilled in the art will recognize that, while throughout this description most state change lines are depicted as straight lines to simplify the description and presentation, in practice the lines would typically be at least partially curved (e.g., a simple heating line is usually a curved line closely matching a logarithmic or exponential line).

The expansion turbine usually drives the compressor turbine and is, therefore, usually situated on the same shaft as the compressor turbine. The shaft may also drive a generator to generate electricity. While a generator is referenced herein, it should be understood that the energy developed my be used by any energy-using device, such as generator. In the case of directly coupled turbines, the gas turbine system or arrangement does not drive a generator but may be coupled directly to pumps or other devices that use mechanical power, such as compressors, or, in marine applications, vessel propellers.

The overall energy efficiency of such gas turbine system or arrangement is no more than approximately 35% in practice. In theory, the maximum efficiency for a gas turbine with a compressing ratio of ten and air as working fluid (treated as an ideal gas) is less than 50%. As seen in FIG. 14, the mechanical power represented by the shaded triangle (A-D-E) is not used by the typical gas turbine system, even when operating at the theoretical maximum efficiency.

Combined-cycle gas turbines attempt to improve energy efficiency by using the hot working gases after expansion in the turbine to heat water and produce high pressure steam. The high pressure steam in turn drives a steam turbine to generate additional mechanical or electrical power. Unlike a single-cycle gas turbine system, the hot exhaust gases pass through a heat exchanger/steam generator where they are cooled down before exhaust. The steam components use additional mechanical work.

1. Open-Cycle Gas Turbines with Recuperator and No Co-Generation of Heat and Power

Referring to FIG. 15, a theoretical, schematic S-T diagram of the thermodynamic process carried out by an EVITE gas turbine is presented. With an EVITE gas turbine, the compressor turbine aspires a working gas and compresses the working gas with evaporation of vaporizable liquid while keeping the working gas (gas-vapor mixture) near thermal equilibrium. In some arrangements, the working gas is air and the vaporizable liquid is water. The higher the vapor pressure of the liquid used, the faster the vaporization rate is. Thus, in some cases, a liquid with a higher vapor pressure is desirable. The vaporizable liquid may be droplets injected on intake or in the course of compression so that they are compressed along with the working gas, e.g., air, and completely evaporated as described more fully above. In some arrangements, the compression process includes vaporizing the liquid by passing the working gas through an external tank of vaporizable liquid after one or more compression stages(s) as described above.

The compression of the working gas (e.g., air) with the vaporizable liquid (e.g., water), creates a gas-vapor mixture with a continuously increasing mass fraction of vapor by evaporation in the course of the compression. The compressed working gas is substantially saturated with vapor after compression. The working gas should be as saturated with the vapor as possible after compression to ensure the compression is as near to thermodynamic equilibrium as possible. The addition of a vaporizable liquid to the working gas may cause the compression end temperature to be considerably lower than in the conventional case described with reference to FIG. 14. The compressed gas may be a mixture of the working gas and the vaporized liquid.

The amount of liquid to be vaporized depends on the amount of external thermal power to be provided to the system by the burning fuel or by an external heat exchanger. The amount of vaporizable liquid may be chosen so that the vaporization enthalpy of the liquid at the exhaust temperature is between around 30% and 50% of the thermal power provided by the external thermal power source. If, for example, the thermal power of natural gas burned in the combustion chamber is around 25 MW (which corresponds to burning around 0.5 kg of natural gas per second), then between approximately 3 kg/s and approximately 5 kg/s of water would have a vaporization enthalpy at the exhaust temperature of between around 30% and 50% of 25 MW. This water flow counts for between 7 MW and 12 MW of the condensation power after discharge into the environment. Condensation power refers to the thermal energy released during condensation per unit time by a mass of vapor. One purpose of adding vaporizable liquid during the compression process is to drain thermal energy from the working gas at a temperature near the lower temperature reserve through the condensation of the liquid rather than by simply cooling of the exhaust gas. Thus, the mass of the vaporizable liquid to be provided during the compression process is proportional to the external thermal power provided to the system. In addition, the mass of vaporizable liquid required to drain a certain amount of external thermal power from the system is reduced with a higher vaporization enthalpy of the liquid; more specifically this may be expressed

$\begin{matrix} {M \propto {P\frac{D}{H_{evap}}}} & (1) \end{matrix}$

where M is the mass of vaporizable liquid to be supplied during the compression process, P is the thermal power provided to the system by the combustion process or external heat exchanger, D is the percentage of the external thermal power to be drained (e.g., approximately 40% of P), and dH_(evap) is the specific enthalpy required to vaporize 1 kg of liquid at discharge.

The compressed working gas (gas-vapor mixture) enters the recuperator (i.e., a heat exchanger) where the working gas is pre-heated by the hot expanded gases (state change B→C in FIG. 15). The compressed working gas mixture may leave the recuperator at a temperature of approximately 500° C. and then enters the combustion chamber where fuel is burned, creating exhaust gas (state change C→D). The hot exhaust gas may reach a temperature of approximately 1000° C. The hot exhaust gas leaves the combustion chamber and enters the expansion turbine where the gas may be expanded to ambient pressure and a temperature of approximately 500° C. (state change D→E). The expanded exhaust gas is supplied through the exhaust conduit or channel to the recuperator where the gas may heat the working gas (gas-vapor mixture) from the compressor turbine to approximately 500° C., thus, lowering the exhaust gas temperature to approximately 100° C. (E→F). The cooled exhaust gas is discharged through the outlet into the environment where the gas cools down further by mixing with the ambient air (F→A). One skilled in the art will recognize that the temperatures predicted in this section may vary widely based on the particular gas turbine components and system.

After the exhaust working gas has passed through the recuperator after expansion (i.e., at state F) and has transferred most of its thermal energy to the newly compressed working gas mixture volume of the working gas at the recuperator is considerably higher than after compression (at state B). Consequently, the dew point is lower than the compression end temperature. Therefore, the exhaust gas cools down to the dew point (F→G in FIG. 15) before condensation occurs. For example, the vapor pressure for water at 55° C. is approximately 150 mbar, and the remaining exhaust gas (working gas and other combustion products) has a pressure of approximately 850 mbar corresponding to the difference between the vapor pressure and the ambient atmospheric pressure. Therefore, the exhaust gas may occupy only slightly more volume than a working gas circulating without the addition of vaporizable liquid.

In the beginning of condensation, a large amount of steam condenses and a large amount of condensation energy is liberated within a small temperature range represented by the state change indicated by the condensation line G→A in FIG. 15. The condensation line G→A begins nearly parallel to the entropy axis (S-axis) or absc/ssa. For example, for water vapor at temperatures around 50° C., every decrease of 12 K, lowers the steam pressure by half. In other words, decreasing the temperature starting from point G by approximately 12K will condense half of the steam and release half of the condensation energy stored in the working gas by the water vaporized in the course of the compression (state change A→B). Consequently, the condensation of the steam stored in the working gas approaches an isothermal state change.

A recuperator increases the temperature at which the compressed air enters the combustion chamber. For a combustion chamber entrance temperature of 600° C., a maximum combustion temperature of 1300° C., and average temperature of condensation in the exhaust gas of 55° C., the efficiency of an EVITE cycle may reach approximately 73%.

As described herein, vapor is mainly used as the energy and entropy carrying medium and makes only a minor contribution to power generation through the partial pressure of the vaporized liquid (which is typically not significantly above 10% of the overall pressure of the gas-vapor mixture). In other words, vapor contributes below approximately 25% of the power generated by the system. For example, given that the vapor pressure for water at 55° C. is approximately 150 mbar, the remaining discharged gas (working gas and other combustion products) has a pressure of approximately 850 mbar corresponding to the difference between the vapor pressure and the ambient atmospheric pressure. Therefore, the exhaust or discharge gas may occupy only slightly more volume than a working gas circulating without the addition of vaporizable liquid.

One illustrative embodiment basically builds a combined-cycle power plant in one single engine which can be scaled down to as low as few kW and scaled up to as high as several 100 MW or higher. Existing combined-cycle power plants are usually 100 MW and beyond. Only a small amount of mechanical work, which is indicated in FIG. 15 by the hatched area A-G-H-A, is lost compared to the optimum cycle, which is represented by the area A→B→D→E→H→A. The optimum cycle is dictated by the thermodynamic laws of nature and cannot be surpassed. The theoretical efficiency for the optimum thermodynamic cycle is around 71.3%, while the theoretical efficiency of the thermodynamic cycle implemented by a recuperated EVITE gas turbine arrangement is 68%.

The system components may include a compressor with an isentropic efficiency of 78% (isentropic efficiency in this instance is defined by dividing the theoretically absorbed mechanical energy for a perfectly isentropic process by the actual amount of mechanical energy required by the compression) and an expansion turbine with an isentropic efficiency of 83% (isentropic efficiency in this instance is defined by dividing the actual amount of mechanical energy delivered by expansion by the theoretically deliverable mechanical energy for a perfectly isentropic process), leading to a real efficiency of around 54% for some embodiments operating at the temperatures and pressures indicated above.

2. Open-Cycle Gas Turbines for Co-Generation of Heat and Power

Referring to FIG. 16, an open-cycle gas turbine system 1601 for the combined production (also termed co-generation) of heat and power (CHP) in which the thermal energy for CHP is extracted immediately after compression when the dew point is higher due to the increased density of the working gas after compression. FIGS. 17 a, 17 b, and 17 c show the thermodynamic cycle carried out by the system 1601 shown in FIG. 16 during maximum heat production, maximum electricity production, and mixed heat and electricity production, respectively. The amount of thermal energy extracted from the system 1601 may be varied dynamically according to the actual requirements of the external consumer (e.g., building heating).

Both heat and power can be produced independently by the same system 1601 with minor variations in the thermal efficiency. For example, at full thermal load, the power producing efficiency may be approximately 50% of the optimum thermal cycle as indicated by the cross-hatched (or shaded) portion of FIG. 17 a. When producing power only (no heat), the efficiency of the system 1601 may be approximately 53% of the optimum thermal cycle as indicated by the cross-hatched portion of FIG. 17 b. At approximately 50% of full heat load, then the power production efficiency may be approximately 51.5% of the optimum thermal cycle as indicated by the cross-hatched portion of FIG. 17 c. The electricity produced also varies with the power production efficiency, but can be kept constant by burning slightly more fuel.

In an illustrative open-cycle gas turbine system 1601 with recuperator and co-generation of heat and power, the system 1601 includes a compressor turbine 1620, a heat exchanger 1621, a recuperator 1622, an internal combustion chamber 1623, and an expansion turbine 1624. The compressor turbine 1620 aspires ambient a working gas, e.g., air, at inlet 1603 and compresses the working gas with the evaporation of vaporizable liquid 1605, or VL. The compression process may include a vaporizable liquid delivery device 1640 that introduces vaporizable liquid into compressor 1620. The vaporizable liquid delivery device may be one or more injectors on compressor 1620, a nozzle for introducing liquid at inlet 1603, vaporizable liquid—preferably liquid droplets—into the working gas. The vaporizable liquid delivery device 1640 may provide continuous evaporation of small droplets of vaporizable liquid (e.g., water or fuel) in the compressor 1620. Vaporizable liquid may also be supplied via external tanks as described above. The external tanks effectively replace external intercoolers.

The vaporizable liquid may be a mixture of various fluids, including a mixture of a non-flammable liquid and fuel. The liquid droplets may be introduced by injection in the course of compression so that they are rapidly compressed along with the air. Alternatively, the liquid droplets may be introduced at inlet 1603. The compressed working gas, e.g., air, is substantially saturated with water vapor after compression, i.e., by the end of compression. If fuel is used as the vaporizable liquid, enough fuel is injected to exceed the ignition condition so that ignition is not possible.

The vaporization of the fuel in the compressor 1620 occurs so quickly that the ignition condition for the vaporizable fuel is not reached. In cases where fuel is supplied and vaporized in external tanks, the first compressor stage 1620 reaches a high enough pressure that the ignition condition is not met in the first tank.

The compressed working gas (mixture) then is delivered by conduit 1607 to the heat exchanger 1621, where the working gas is cooled and the vaporizable liquid is condensed to extract a portion of the thermal energy in the working gas (mixture). Because the pressure and density of the working gas (gas-vapor mixture) is higher after compression than after expansion, the dew point is higher and thermal energy is produced at a higher temperature. If the vaporizable liquid includes fuel, enough fuel vapor is condensed that the fuel concentration is insufficient to allow ignition without the addition of more heat. The amount of condensed fuel vapor may be adjusted in such a manner that the remaining fuel can be completely burned with the oxygen of the aspired air.

By increasing or decreasing the amount of coolant circulating in coolant conduit 1630 through the heat exchanger 1621, the amount of vapor condensed from the compressed working gas (gas-vapor mixture) can be varied dynamically. As more coolant passes through the heat exchanger 1621, the temperature of coolant after passing through the heat exchanger 1621 decreases and the dew point of the working gas (gas-vapor mixture) after passing through the heat exchanger 1621 is reduced. Consequently, more vapor condenses and more thermal energy is transferred to the coolant. A coolant controller 1632 may be used to dynamically adjust the coolant circulating in coolant conduit 1630, which may be open or closed.

The condensed liquid may be recycled by transporting the condensed liquid in conduit 1609 and injecting the condensed liquid into the compressor 1620. To produce maximum heat, as much vapor as possible should be condensed, allowing the working gas (mixture) to transfer substantially all of its thermal energy to heat consumers. The condensate used for heating is removed through thermal-energy delivery conduit 1611. To produce maximum electricity, little to no condensation occurs in the heat exchanger 1621. The amount of condensed steam is freely adjustable to continuously shift the operation between heat-controlled and power-controlled schemes.

The cooled, compressed working gas (mixture) then is delivered by conduit 1613 to the recuperator 1622 (i.e., a heat exchanger for “recouping” the heat from the exhaust gases) where the working gas is heated by the hot exhaust working gas from the expansion turbine 1624. The compressed working gas (mixture) leaves the recuperator and is delivered by conduit 1615 to the combustion chamber 1623 where fuel is burned, creating an exhaust gas (hot working gas). In some cases, if fuel is used as the vaporizable liquid, no additional fuel is required to be added in the combustion chamber 1623. The hot exhaust gas leaves the combustion chamber 1624 and is delivered by conduit 1617 to the expansion turbine 1624 where the exhaust gas is expanded. The expansion turbine 1624 removes energy from the compressed hot working gas that may be used to accomplish useful work, such as generate electricity. Generator 1628 is shown associated with expansion turbine 1624 but many other uses may be made of the energy. It should be noted that herein the devices and means for removing energy from the expansion turbines are not explicitly nor generally shown. FIG. 16 does, however, show removal.

The expanded exhaust gas is supplied through the exhaust conduit 1619 or channel to the recuperator 1622 where the expanded exhaust gas heats the compressed working gas (i.e., the compressed air and vapor mixture) required from the compressor turbine 1620. The cooled exhaust gas is discharged through the outlet 1625 into the environment where cooled exhaust gas cools down further by mixing with the ambient air.

3. Open-Cycle Gas Turbine

Referring now to FIG. 18, a schematic diagram of an illustrative open-cycle gas turbine system 1801 is presented. FIG. 19 is a theoretical, schematic S-T diagram of the thermodynamic process of the system 1801 shown in FIG. 18. The illustrative open-cycle gas turbine system 1801 includes a compressor turbine 1840, which includes four radial turbine stages, an inter-cooler 1846 connected to the compressor turbine 1840 via channels 1841, a recuperator 1842, a combustion chamber 1843, and an expansion turbine 1844. The compressor stages of compressor 1840 compress an aspired working gas, e.g., air, raising the pressure and temperature.

After the first compressor stage the compressed and heated working gas is taken out through the channel 1841 a and delivered to the inter-cooler 1846 where the compressed working gas is cooled down. The cooled working gas is returned via channel 1841 b to the subsequent compressor stage which, in turn, compresses the cooled working gas further. After that stage, the channel 1841 c directs the more compressed and, hence, heated working gas again out of the compressor turbine 1840 and delivers the working gas to the inter-cooler 1846 for cooling before the channel 1841 d returns the cooled working gas to the next stage of the compressor turbine 1840 for further compression. After the next stage, channel 1841 e delivers the heated and compressed working gas to the inter-cooler 1846 for cooling and returns the working gas to the 4^(th) and last compressor stage of the turbine 1840. More or less compressor staged might be used.

The compressed and heated working gas leaves the last compressor stage and is delivered by conduit 1803 to the recuperator 1842. The working fluid then passes through the recuperator 1842 and is heated by the hot exhaust gas from the expansion turbine 1844. No inter-cooling is provided after the last compressor stage. The working gas is then delivered by conduit 1805 to the combustion chamber 1843. In the combustion chamber 1843 the compressed and pre-heated working gas burns the fuel to produce a hot working gas. The hot working gas is delivered by conduit 1807 to the expansion turbine 1844 where the hot working gas is expanded to ambient pressure and a temperature of around 500° C. and thereby produces an exhaust working gas. The exhaust working gas, or exhaust gas, from the expansion turbine 1844 is delivered by conduit 1809 to the recuperator 1842 and passes through the recuperator 1842 to heat the compressed working gas from the compressor turbine 1840. The exhaust working gas is then discharged into the environment through the exhaust 1845.

4. Open-Cycle Gas Turbines with Heat Exchanger Between Expansion Turbine and Recuperator for Co-Generation of Heat and Power

Referring now to FIG. 20, an illustrative open-cycle gas turbine system 2001 for CHP is presented. FIG. 21 is a theoretical, schematic S-T diagram of the thermodynamic process carried out by the system 2001 shown in FIG. 20. The open-cycle gas turbine with recuperator and co-generation of heat and power system 2001 includes a compressor turbine 2010, a recuperator 2011, an internal combustion chamber 2012, an expansion turbine 2013, and a heat exchanger 2014.

The compressor turbine 2010 aspires a working gas, e.g., ambient air, through inlet 2002 and compresses the working gas with the evaporation of vaporizable liquid provided by a vaporized liquid delivery device 2003. The compression process may occur under continuous evaporation of small droplets of vaporizable liquid (e.g., water) from the vaporizable liquid delivery device 2003. Liquid droplets may be introduced by vaporizable liquid delivery device 2003 during the course of compression so that they are compressed along with the working gas. Vaporizable liquid may also be supplied via external tanks as described above. Alternatively, the droplets are injected by device 2003 into the air during intake at inlet 2002. The external tanks effectively replace any external intercoolers and may more thoroughly saturate the compressed gas. The compressed working gas is substantially saturated with liquid vapor after compression.

The compressed working gas (mixture) then is delivered by conduit 2005 to the recuperator 2011. The compressed working gas enters the recuperator 2011 (i.e., a heat exchanger for “recouping” the heat from the exhaust gases) where the working gas is heated by the hot exhaust gas from the expansion turbine 2013. The compressed working gas (mixture) leaves the recuperator 2011 through conduit 2007 and enters the combustion chamber 2012 where fuel is burned, creating an exhaust gas, or hot exhaust working gas. The hot exhaust gas leaves the combustion chamber 2012 through conduit 2009 and enters the expansion turbine 2013 where the hot exhaust gas is expanded to ambient pressure and energy removed.

The expanded exhaust gas is then supplied through an exhaust conduit or channel 2016 to the heat exchanger 2014 where the exhaust gas is cooled to extract a portion of the thermal energy from the exhaust gas and forms a cooled exhaust gas. The cooled exhaust gas then is delivered by conduit 2018 to the recuperator 2011 where the cooled exhaust gas heats the compressed working fluid (air and vapor mixture) from the compressor turbine 2010. Then, the cooled exhaust gas leaving the recuperator 2011 is discharged through the outlet 2015 into the environment where working gas cools down further by mixing with the ambient air. If recovery of the vaporizable liquid is desired, a condenser may be introduced between the recuperator 2011 and exhaust 2015 or between the compressor turbine 2010 and the recuperator 2011.

The system 2001 generates heat at higher temperatures than the system 1601 of FIG. 16. For example, temperatures between approximately 100° C. and approximately 500° C. can be generated using air and water. Applications for this system 2001 may include producing combustible gases from biomass or other substances (i.e., removing water and to starting molecular break-up) and distilling of liquids with higher evaporation points (e.g., mid-heavy and heavy hydrocarbons).

5. An Open Cycle Aircraft Gas Turbine Engine with a Recuperator and EVITE Compressor Using Vaporizable Fuel

Referring to FIG. 22, an illustrative turbo fan engine 2200 with a recuperator is presented. FIG. 23 is a theoretical, schematic S-T diagram of the thermodynamic process carried out by the turbo fan engine 2200 shown in FIG. 22. The turbo fan engine 2200 with a recuperator includes a fan 2201, an inter-stage compressor 2202, a cooler-condenser 2203, a pump 2209, a recuperator 2204, a combustion chamber 2205, a first and an optional second expansion turbine 2206, 2207, and a nozzle 2208. The fan 2201 slightly compresses and accelerates a larger amount of air than is channelled through the gas turbine. Typically, the air accelerated by the fan 2201 is cold air at flight altitudes. The compressor 2202 aspires a portion of the air compressed by the fan and compresses the air in stages, e.g., stages 2210 a, 2210 b, 2210 c, 2210 d, 2210 e, 2210 f, 2210 g, 2210 h.

Vaporizable fuel is introduced between the stages or between groups of stages by a vaporizable liquid delivery device 2216, e.g., injections. The fuel may be preheated to a temperature approximately equal to the temperature at which gas-vapor mixture leaves each previous stage or group of stages. In some cases, the fuel may be preheated to a higher temperature before being introduced after the initial stage or group of stages to increase the vaporization rate. In some cases, the fuel may be introduced into a circumferential injection chamber analogous to those described above with reference to FIG. 3. For example, small vaporizable fuel droplets are injected after each compression stage and are vaporized before each subsequent stage in a manner analogous to that described in Section I.A.2 regarding the inter-stage injection of vaporizable liquid. Alternatively, the vaporizable fuel may be supplied via external tanks. The external tanks are more feasible if the tanks weigh no more than the weight that is saved by the reduction in fuel consumption and the reduction in component size due to this turbo fan engine arrangement. Enough fuel is provided that the fuel-gas mixture exceeds the ignition condition so that ignition is not possible. The compressed air is saturated or nearly saturated with fuel vapor after compression.

The compressed mixture then enters the cooler-condenser 2203 and is cooled by the cold air compressed by the fan. The majority of the vaporized fuel is condensed in the cooler-condenser 2203 so that insufficient fuel is present in the mixture to allow ignition. The condensed fuel is returned to the compressor for re-injection by the pump 2209. The cooled, compressed and dried air/fuel mixture passes through the recuperator 2204 and is heated by the hot gases from the first expansion turbine 2206. Additional fuel is injected with the compressed air/fuel mixture heated by the recuperator, and burned, along with the remaining vaporized fuel, in the combustion chamber 2205. Then, the hot working gas is expanded in the first expansion turbine 2206 before entering the recuperator 2204 to heat the working gas from the cooler-condenser 2203. The first expansion turbine 2206 may expand the working gas to an intermediate pressure above ambient pressure. The partially expanded working gas may then be expanded further in the optional second expansion turbine 2207 to increase the efficiency of the system. Finally the working gas is released through the nozzle 2208 to mix with the cool air that entered the fan 2201 and passed through the cooler-condenser but bypassed the remainder of the engine.

6. An Aircraft Gas Turbine Engine with Initial Compression with Vaporizable Fuel and a Second Compressor

Referring to FIG. 24, an illustrative turbo fan engine 2420 is presented. FIG. 25 is a theoretical, schematic S-T diagram of the thermodynamic process carried out by the turbo fan engine 2420 shown in FIG. 24. The turbo fan engine 2420 with two compressors includes a fan 2421, a multi-stage compressor 2422, a second compressor 2424, a cooler-condenser 2423, a pump 2428, a combustion chamber 2425, an expansion turbine 2426, and a nozzle 2427. The fan 2421 slightly compresses and accelerates a larger amount of air than is channelled through the gas turbine. The compressor 2422 aspires a portion of the air compressed by the fan 2421 and compresses the air in stages.

Vaporizable fuel is introduced between the stages or between groups of stages by a vaporizable liquid delivery device 2436, e.g., injections. The fuel may be preheated to a temperature approximately equal to the temperature at which the compressed gas-vapor mixture leaves each stage. Alternatively, the fuel may be preheated to a higher temperature before the first stage or the early stages. For example, small vaporizable fuel droplets are injected after each compression stage and are vaporized before each subsequent stage analogous to those described in Section I.A.2 regarding the inter-stage injection of vaporizable liquid. Alternatively, the vaporizable fuel may be supplied via external tanks. The external tanks are more feasible if the tanks weigh no more than the weight that is saved by the reduction in fuel consumption and the reduction in component size due to this turbo fan engine arrangement. Enough fuel is provided that the fuel-gas mixture exceeds the ignition condition so that ignition is not possible. The compressed air is saturated or nearly saturated with fuel vapor after compression.

The compressed mixture then enters the cooler-condenser 2423 and is cooled by the slightly compressed and generally cooler air from the fan 2421. The majority of the vaporized fuel is condensed in the cooler-condenser 2423 so that not enough fuel is present in the mixture to allow ignition. The condensed fuel is returned to the compressor for re-injection by the pump 2428. The cooled, compressed and dried air/fuel mixture passes through the second compressor 2424 without adding vaporizable fuel. Additional fuel is injected with the compressed air/fuel mixture and burned, along with the remaining vaporized fuel, in the combustion chamber 2425. Then, the hot working gas is expanded in the expansion turbine 2426 before the working gas is released through the nozzle 2427 to mix with the cool air that bypassed the remainder of the engine through the fan 2421 and the cooler condenser 2423. In some embodiments, before the expanding working gas is released through the nozzle 2427, the gas passes through another expansion turbine.

7. Open Cycle Gas Turbine with Internal Combustion and Exhaust Gas Cleaning

Currently, gas turbines mainly use internal combustion chambers to burn high-quality fuel, such as natural gas or kerosene. On the other hand, solid fuel (coal, biomass, etc.) is available in much larger quantities and at considerably lower prices. In order for lower quality fuel, such as solid fuel, that produces exhaust containing ash and other solid particles to be used, a cost efficient method of removing the particles, which may damage turbine parts from the exhaust, needs to be provided. As such, cleaning devices for removing particles are provided that typically receive the pressurized, high temperature exhaust from the combustion chamber and operate on the exhaust. Devices and methods for removing particles from the exhaust at atmospheric pressure are now described with reference to FIGS. 26 and 27.

Referring to FIG. 26, an open-cycle gas turbine system 2600 or arrangement with internal combustion and exhaust gas cleaning is presented. FIG. 27 shows the thermodynamic process carried out by the system 2600 shown in FIG. 26. The open-cycle gas turbine system 2600 with internal combustion and exhaust gas cleaning includes a recuperator 2641, a combustion chamber 2642, a cleaning chamber 2643, an expansion turbine 2644, a gas washer 2645, and a compressor turbine 2646. A working gas, e.g., ambient air, enters the system 2600 at inlet 2640 and passes through the recuperator 2641 to be heated (state change A→B in FIG. 27) by exhaust gas from the expansion turbine 2644 before the working gas enters the combustion chamber 2642 to burn the fuel therein. This combustion process increases the temperature of the working gas, e.g., air, (state change B→C in FIG. 27).

The exhaust gas from the combustion chamber 2642 is delivered to cleaning chamber 2643 and is cleaned in the cleaning chamber 2643. No part of the exhaust gas has been compressed and so the pressure of the exhaust gas is still at approximately ambient level. Thus, no significant pressure is exerted on the combustion chamber 2642 or the cleaning chamber 2643. As such, the cleaning chamber 2643 can be relatively large without requiring walls capable of withstanding high pressure. The cleaning chamber 2643, which can be large, ensures a long transit time for the exhaust gas to be processed for cleaning. For example, the exhaust gas may pass through several cyclones to deposit any solid ash components produced in the course of combustion. Electrical filters or the like may also be provided in connection with cleaning chamber 2643 for additional cleaning in the large cleaning chamber 2643. The cleaned exhaust gas leaves the cleaning chamber 2643 at approximately ambient pressure and is supplied to the expansion turbine 2644 for expansion to a lower pressure (state change C→D in FIG. 27) to produce a depressurized exhaust gas.

The de-pressurised exhaust gas then passes through the recuperator 2641 and cools down by transferring thermal energy to the aspired air (state change D→E in FIG. 27). The recuperator 2641 may include a filter to remove any additional particles from the depressurized exhaust gas, especially any ashes which condense and/or crystallize at lower temperatures. The exhaust gas leaves the recuperator 2641 at a lower temperature and substantially the same pressure and is delivered to gas washer 2645.

In the gas washer 2645, the exhaust gas is further cleaned from any produced ash particles and other products which might damage the subsequent compressor turbine 2646. Because the temperature in the gas washer is low, washing can be performed by a wide variety of washing fluids, for example, by water. In some cases, the washing fluid may contain additives to aid in removing or dissolving solid components in the exhaust gas. This water may later be filtered or processed in another way to remove the particles. The washed exhaust gas leaves the gas washer 2645 at a lower temperature and the substantially the same pressure and is delivered to compressor turbine 2646.

In the compressor turbine 2646, the cleaned exhaust gas together with a vaporizable liquid, which is supplied by a vaporizable liquid delivery device 2602, is compressed in a substantially isentropic manner to approximately ambient pressure (state change ELF in FIG. 27). As one illustrative non-limiting example, the liquid may be water. The compression end temperature is slightly raised depending on the initial water content of the fuel burned in the combustion chamber 2542. If the fuel includes water or water is produced by the combustion process, the dew point of the gas-vapor mixture is higher and the corresponding compression end temperature is also higher. The re-compressed exhaust/steam mixture is discharged through the outlet 2647 into the environment and the steam may condense or be diluted by mixing with ambient air. Optionally, the steam in the discharged exhaust gas may be condensed by a cooler-condenser (not shown) to re-circulate the water for compression and/or washing.

8. Open Cycle Gas Turbine with Heat Exchanger, External Combustion Chamber and No Co-Generation of Heat and Power

Currently, gas turbines mainly use internal combustion chambers to burn high-quality fuel, e.g., natural gas or kerosene. On the other hand, solid fuel (coal, garbage, straw, bagasse, biomass, etc.) is available in much larger quantities and at considerably lower prices, but using solid fuel like this presents problems. In one approach, the externally fired gas turbine cycle uses a high temperature heat exchanger to heat the compressed working gas before expansion. The heat exchanger is heated by the hot flue gases from an external combustion chamber where solid fuel is burned. The efficiency of the thermodynamic cycles of these gas turbine arrangements, however, is generally poor for gas turbines with high compression ratios.

According to an improved, illustrative embodiment, an open-cycle, external combustion gas turbine, compresses gas with a vaporizable liquid, preheats the mixture using exhaust gas, and expands the preheated mixture before channeling the gas to the external combustion chamber. Thus, only a mixture of air and vapor passes through the gas turbine components and any contact with combustion products is avoided.

For example, the split-stream embodiment shown in FIG. 28 allows for a greater difference between the combustion end temperature and the expansion turbine inlet temperature without compromising engine efficiency. The open-cycle gas turbine system 2810 with recuperator and external combustion chamber without the co-generation of heat and power includes a compressor turbine 2800, a medium temperature heat exchanger 2801, a high temperature heat exchanger 2802, an expansion turbine 2803, a valve 2804, and an external combustion chamber 2805.

The compressor turbine 2800 aspires a working gas, e.g., ambient air, through inlet 2807 and compresses the working gas with the evaporation of vaporizable liquid provided by a vaporizable liquid delivery device 2808. The compression process may occur under continuous evaporation of small droplets of vaporizable liquid (e.g., water). The droplets are injected into the air during intake or, as shown, during the course of compression so that they are compressed along with the working gas. Vaporizable liquid may also be supplied via external tanks as described above. The compressed working gas is substantially saturated with steam after compression. The compressed working gas is delivered to first medium temperature heat exchanger 2801 by conduit 2811.

The compressed mixture is heated in the first medium-temperature heat exchanger 2801 and then delivered to the second high temperature heat exchanger 2802 where the working gas is further heated. The first medium-temperature heat exchanger 2801 is heated by both a first stream corresponding to the part of the hot working gas diverted by the valve 2804, after expansion, to conduit 2812. The gas in conduit 2812 does not reach the external combustion chamber 2805. The first medium temperature heat exchanger 2801 is also provided heat by a second stream corresponding to the cooled exhaust gas that has passed through the second high temperature heat exchanger 2802 and is delivered by conduit 2814. Each stream heats a mass fraction of the compressed air stream proportional to the respective stream's mass fraction of the overall exhaust gas stream. The once-heated working gas is delivered from the medium temperature heat exchanger to the high temperature heat exchanger by conduit 2816.

The stream from the high temperature heat exchanger 2802 delivered by conduit 2814 and the stream diverted by the valve 2804 into conduit 2812 may be mixed before passing through the medium-temperature heat exchanger 2801 and may flow together through the medium-temperature heat exchanger 2801 as shown in FIG. 29 a. In some cases the two streams flow together in countercurrent exchange with the flow from the compressor. Alternatively, the two streams (conduits 2812 and 2814) may remain separate as they flow through the medium-temperature heat exchanger 2802 as shown in FIG. 29 b and may exit through separate outlets 2806 a and 2806 b. In some cases, the medium temperature heat exchanger may be a cross-current heat exchanger or a rotating recuperator or any other known type of heat exchanger.

The high temperature heat exchanger 2802 is directly heated by the hot exhaust gas from the external combustion chamber 2805 and heats the working gas delivered by conduit 2816 to produce a twice heated, compressed working gas. The twice heated, compressed mixture is then expanded in the expansion turbine 2803 before being split into two streams by the valve 2804. The first stream then passes by way of conduit 2812 directly through the medium-temperature heat exchanger 2801 and heats a portion of the newly compressed working gas as described above.

The second stream is delivered by conduit 2818 to the external combustion chamber 2805 and combusts with the fuel to produce hot exhaust gases that are introduced into conduit 2820. Combustion is possible because at the combustion chamber temperature shown only part of the oxygen content of the aspired air is required. Because the amount of burned fuel per air mass is higher, the combustion temperature at which the flue gases leave the external combustion chamber 2805 is higher than when all of the working gas is used for combustion. In the example shown, the temperature of the flue gases created by burning fuel with only the second stream is approximately 1500° C., as opposed to approximately 850° C. if burning the fuel with the entire compressed air mass. Alternatively, the valve 2804 may be a gas separator that sends oxygen to the external combustion chamber 2805 as the second stream and the remaining working gas to the medium-temperature heat exchanger 2801 as the first stream. In this case the temperature of the flue gases may be above approximately 2000° C., but this may damage the combustion chamber 2805 or produce more NOx.

The hot exhaust gas passes from the combustion chamber 2805 through the high temperature heat exchanger 2802 and then is delivered by conduit 2814 to the first medium-temperature heat exchanger 2801 where the exhaust gas helps to heat the newly compressed working gas from the compressor turbine 2800. The amount of gas available after combustion is only the part of the initial compressed working gas in conduit 2822. Thus, in the case shown in FIG. 28 and for the illustrative example, the thermal energy provided to the compressed working gas delivered in conduit 2816 by the high temperature heat exchanger 2802 corresponds to the energy required to heat the entire amount of working gas delivered by conduit 2816 from approximately 400° C. to approximately 850° C.

After heating the compressed working gas from the medium-temperature heat exchanger 2801 in the high temperature heat exchanger 2802, the hot flue gas, or exhaust gas, from the external combustion chamber 2805 cool down to approximately 400° C. and are delivered by conduit 2814 to the medium-temperature heat exchanger 2801. The exhaust gas then heats a portion of the working gas from the compressor turbine 2800 which is proportional to the mass of the second stream. Afterwards the flue gas, or exhaust gas, is discharged into the environment through the exhaust outlet 2806 together with the cooled first stream.

High temperature heat exchangers are generally expensive. As discussed above, the effectiveness of the heat transfer increases with the temperature difference between the gas stream to be heated and the gas stream which provides the thermal energy and, consequently, is cooled. On the other hand, minimizing the temperature difference between the heated stream and the stream to be cooled increases the thermal efficiency of the gas turbine. Thus gas turbine designers typically must choose between smaller, low cost heat exchangers and low efficiency gas turbines or high costs and high efficiency. By splitting the working gas stream into two parts after expansion so that only one part is used to burn the solid fuel, the combustion temperature at which the flue gases leave the external combustion chamber 2805 is higher than when all of the working gas is used for combustion. This allows the size of the high temperature heat exchanger 2802 to be reduced. In addition, the temperature difference between the flue gas from the external combustion chamber 2805 and the compressed working gas may be higher.

Even if the material of heat exchanger 2802 cannot support temperatures higher than the 850° C., the temperature gradient between the flue gases from the combustion chamber 2805 and the material can be raised if the high temperature heat exchanger 2802 material is sufficiently cooled so the high temperature heat exchanger 2802 may be smaller. This lowers the costs of the externally fired gas turbine arrangement.

10. Open-Cycle Gas Turbines with External Combustion Chamber and Co-Generation of Heat and Power

Externally fired gas turbines can be used for combined heat and power production (CHP). However, the same problems apply as in internally fired gas turbines operating in CHP.

a. Open-Cycle Gas Turbines with External Combustion Chamber and Co-Generation of Heat and Power with a Low Temperature Heat Exchanger and a High Temperature Heat Exchanger

Referring to FIG. 30, an illustrative open-cycle gas turbine system 3000, or arrangement, for CHP with external firing is presented. FIG. 31 is a theoretical, schematic S-T diagram of the thermodynamic process carried out by the system 3000 shown in FIG. 30. The open-cycle gas turbine system 3000 includes a compressor 3010, a low temperature heat exchanger 3011, a high temperature heat exchanger 3012, an expansion turbine 3013, and an external combustion chamber 3014. As used herein, in general terms that may vary, “low temperature” means less than 200 C, medium temperature is <200 C and <500 C; and high temperature is >500 C.

The compressor turbine 3010 aspires a working gas, e.g., air, and compresses the working gas with the evaporation of a vaporizable liquid, such as water provided by a vaporizable liquid delivery device 3018. The compression process may occur under continuous evaporation of small droplets of vaporizable liquid. The droplets are injected into the air during intake or as during the course of compression by the device 3018 so that they are compressed along with the air. Vaporizable liquid may also be supplied via external tanks as described above. The compressed working gas is substantially saturated with steam after compression and is delivered by conduit 3020 to the low temperature heat exchanger 3011.

After compression, the compressed working gas (e.g., air/vapor mixture) is cooled in the first low temperature heat exchanger 3011 to condense a part of the vaporized liquid, which is removed by conduit 3022. The amount of vapor to be condensed is determined by the desired amount of thermal power to be produced and can be varied by adjusting the amount of cooling fluid, or coolant, used in the first low temperature heat exchanger 3011.

Then, the compressed, once-heated working gas (e.g., mixture of air and the remaining uncondensed vapor) is delivered by conduit 3024 to and heated in the high temperature heat exchanger 3012. The heated working gas (mixture) is delivered by conduit 3026 to and expanded by the expansion turbine 3013. The expanded working gas, or hot exhaust gas, is guided to the external combustion chamber 3014 by conduit 3028. In combustion chamber 3014, the exhaust gas combines with the fuel and combusts to produce hot exhaust gas. The hot exhaust gas is delivered by conduit 3030 to the high temperature exchange 3012. The hot exhaust gas passes through the high temperature heat exchanger 3012 and transfers heat to the working gas (mixture of air, condensing the remaining uncondensed vapor) before entering the environment through exhaust outlet 3015.

b. Open-Cycle Gas Turbines with External Combustion Chamber and Co-Generation of Heat and Power Using Split Gas Streams

Referring to FIG. 32, an illustrative open-cycle gas turbine system 3200 or arrangement for CHP with external firing is presented. The open-cycle gas turbine system 3200 includes a compressor 3220, a low temperature heat exchanger 3221, a medium temperature heat exchanger 3222, a high temperature heat exchanger 3223, an expansion turbine 3224, a valve 3225, and an external combustion chamber 3226 containing fuel.

The compressor turbine 3220 aspires a working gas, e.g., air, through inlet 3202 and compresses the working gas with the evaporation of a vaporizable liquid, such as water, provided by vaporizable liquid delivery device 3204. The compression process may occur under continuous evaporation of small droplets of vaporizable liquid. The droplets are injected into the working gas during intake or as shown during the course of compression by the device 3404 so that they are compressed along with the working gas. Vaporizable liquid may also be supplied via external tanks as described above. The compressed working gas is substantially saturated with steam after compression and is delivered by conduit 3206 to the low temperature heat exchanger 3221. The amount of injected vaporizable liquid is preferably adjusted in such a manner that all of the liquid vaporizes in the compressor 3220, i.e., the compressed working gas leaving the compressor is just saturated with the vapor.

After compression, the working gas (air/vapor mixture) is cooled in a first low temperature heat exchanger 3221 to condense a part of the vaporized liquid, which is removed by conduit 3208. The amount of vapor to be condensed is determined by the desired amount of thermal power to be produced and can be varied by adjusting the amount of cooling fluid, or coolant, (not shown) used in the first low temperature heat exchanger 3221.

After passing through the low temperature heat exchanger 3221, the working gas (air/vapor mixture) is delivered by conduit 3210 to the medium temperature heat exchanger 3221 and heated. The medium-temperature heat exchanger is heated by a part of the hot exhaust gas diverted by the valve 3225 to conduit 3212 after expansion so that this portion of the exhaust gas does not reach the external combustion chamber 3226. The medium temperature heat exchanger 3222 is also provided thermal energy by the cooled exhaust gas from conduit 3214 that has passed through the high temperature heat exchanger 3223.

After passing through the medium-temperature heat exchanger, the working gas (air/vapor mixture) is delivered by conduit 3216 and further heated in the high temperature heat exchanger 3223. The high temperature heat exchanger 3223 is heated by the hot exhaust gas delivered by conduit 3218 from the external combustion chamber 3226, which receives exhaust gas through conduit 3230. After passing through the high temperature heat exchanger, the working gas (e.g., air/vapor mixture) is delivered by conduit 3232 to and expanded by the expansion turbine 3224 to produce an expanded, exhaust gas.

Then, the expanded exhaust gas, or expanded working gas (e.g., air/vapor mixture) is delivered by conduit 3234 and is split into two streams by the valve 3225. The first stream passes via conduit 3212 directly through the medium-temperature heat exchanger 3222, and the second stream enters via conduit 3230, the combustion chamber 3226 to burn the fuel to produce hot exhaust gas which passes first through the high temperature heat exchanger 3223 and afterwards through the medium-temperature heat exchanger 3222, thereby heating the newly compressed working gas (e.g., air/vapor mixture). After passing through the medium-temperature heat exchanger 3222, the twice-heated working gas (air/vapor mixture) from the compressor turbine 3220 passes through the high temperature heat exchanger 3223.

11. Open-Cycle Gas Turbines with Recuperator between Two Expansion Turbines

Referring to FIG. 33, an illustrative open-cycle gas turbine system 3312 with two-staged expansion before and after the recuperator, which allows the system to recover any additional energy left in the exhaust gas after passing through a recuperator is presented. The efficiency of this system 3312 may reach approximately 60% when using turbines with high efficiency. In addition, this system 3312 performs well at lower compression and expansion ratios—typically pressure ratios between approximately 3:1 and approximately 20:1. FIG. 34 is a theoretical, schematic S-T diagram of the thermodynamic process carried out by the system 3312 shown in FIG. 33. The open-cycle gas turbine system 3312 includes a compressor 3300, a recuperator 3301, a high temperature heat exchanger 3302 or combustion chamber, first and second expansion turbines 3303, 3304, and an optional cooler condenser 3305. The compressor 3300 and expansion turbines 3303, 3304 may be mounted on the same shaft 3309 and used to drive a generator 3306 to produce electricity.

The compressor turbine 3300 aspires a working gas, e.g., ambient air, through inlet and compresses the working gas under continuous evaporation of small droplets of vaporizable liquid (e.g., water) supplied by a vaporizable liquid delivery device 3316. The droplets are injected during air intake or as shown in the course of compression so that they are compressed along with the working gas. Alternatively, the vaporizable liquid may be vaporized in external tanks, in inter-stage injection/vaporization spaces or in injection chambers. Thus, the compression process is carried out near saturation. The compressed air is substantially saturated with vapor after compression and is delivered by conduit 3318 to the recuperator 3301. The compressed working gas then passes through the recuperator 3301 and is heated by the hot gas from the first expansion turbine 3303.

Then, the working gas is delivered by conduit 3320 to the high temperature heat exchanger 3302 or combustion chamber if the combustion products would not damage the turbines 3303, 3304. At the high temperature exchanger/combustion chamber 3302, where the working gas is further heated. The once-heated working gas is then delivered by conduit 3322 to a first expansion turbine 3303.

The heated working gas is expanded adiabatically in the first expansion turbine 3303 and then delivered by conduit 3324 to the recuperator 3301 before passing through the recuperator 3301. The expansion ratio of the first expansion turbine 3303 may be approximately equal to the compression ratio divided by expansion ratio of the second expansion turbine 3304. As the compression end temperature is increased, more thermal energy is lost in the exhaust gas.

After the recuperator 3301, the working gas is delivered by conduit 3326 to and expanded further by the second expansion turbine 3304. The working gas is expanded to the base or ambient pressure. The second expansion turbine 3304 recovers energy remaining in the exhaust after passing through the recuperator 3301. The second expansion turbine 3304 may have an expansion ratio such that the temperature of the exhaust gas after the second expansion is near the dew point of the exhaust gas. The second expansion turbine 3304 may have an expansion ratio between approximately 1.5 and 4. The fully expanded mixture is then discharged into the environment through exhaust outlet 3328.

Alternatively, the expanded working gas (gas/steam mixture) may be cooled further in the optional cooler-condenser 3305 so as to condense the liquid vaporized in the course of compression before discharge. The vaporizable liquid can then be re-circulated by conduit 3302 and pump 3308 and mixed with the working gas to be compressed.

12. Open-Cycle Gas Turbines with Recuperator between Two Compression Turbines

Referring to FIG. 35, an illustrative open-cycle gas turbine system 3500 with compression before and after the recuperator is provided. If the first compression stage or first compressor turbine 3520 raises the compression end temperature too high to allow sufficient heat recovery in the recuperator 3521, a second compressor turbine 3522 in the exhaust stream after the recuperator 3521 can be added. The efficiency of this system 3500 may reach approximately 60% when using high efficiency turbines currently available. The use of improved turbines as part of the system 3500 may raise the efficiency of the system 3500 above approximately 60%. In addition this system 3500 performs well at lower compression and expansion ratios, typically pressure ratios between approximately 3:1 and approximately 20:1. FIG. 36 is a theoretical, schematic S-T diagram of the thermodynamic process carried out by the system 3500 shown in FIG. 35.

The open-cycle gas turbine system 3500 includes first and second compressors 3520, 3522, a recuperator 3521, a combustion chamber 3523, and an expansion turbine 3524. The compressors and expansion turbines may be mounted on the same shaft 3526 and used to drive a generator 3527 to produce electricity. The first compressor turbine 3520 aspires a working gas, e.g., ambient air, at inlet 3502 and compresses the working gas with the evaporation of vaporizable liquid provided by vaporizable liquid delivery device 3504. Preferably, the compression process in compressor 3520 involves the minimal temperature increase possible given the mechanical limitations of the compressor 3520. The compression process may occur under continuous evaporation of small droplets of vaporizable liquid (e.g., water) provided by device 3504. The droplets are injected into the air during intake or during the course of compression so that they are compressed along with the working gas. Vaporizable liquid may also be supplied via external tanks as described above. The compressed gas is saturated with vapor after compression and delivered by conduit 3506 to the recuperator 3521.

The compressed working gas passes through the recuperator 3521 and is heated by the hot gas from the first expansion turbine 3524. After the recuperator 3251, the working gas is delivered by conduit 3508 to the second compressor 3522 to further heat the working gas (gas-vapor mixture), and thereby increases the temperature at which the working gas enters the combustion chamber 3523. The working gas is delivered by conduit 3510 from the second compressor 3522 to the combustion chamber 3523.

After passing through the first and second compressors 3520, 3522, the working gas passes to the combustion chamber 3523 where the working gas combines with fuel and combusts to produce a hot exhaust gas. The hot exhaust gas is delivered by conduit 3512 to and expanded in the expansion turbine 3524. The expanded working gas is delivered by conduit 3514 to the recuperator 3521. In the recuperator 3521 the expanded working gas is used to transfer thermal energy to the newly compressed working gas from the first compressor turbine 3520. The expanded working gas (gas/steam mixture) may be then discharged into the environment through exhaust outlet 3525.

13. Open-Cycle Gas Turbine with Heat Exchanger between Two Compression Turbines

Referring to FIG. 37, an illustrative open-cycle gas turbine system 3700 with compression and recovery of the vaporizable liquid before the second adiabatic compression takes place is presented. Under certain circumstances it may be beneficial not only to recover the injected vaporizable liquid but to replace the recuperator with an additional adiabatic compressor. Especially in mobile applications (e.g., cars or airplanes), the use of an additional compressor instead of a recuperator may be more advantageous with respect weight because in most cases a compressor is lighter than a recuperator. System 3700 is an illustrative embodiment of such a system.

The open-cycle gas turbine system 3700 includes first and second compressors 3780, 3784, a cooler-condenser 3781, a pump 3783, a combustion chamber 3785 (or high temperature heat exchanger) to provide external thermal energy, and an expansion turbine 3786. The compressors 3780, 3784 and expansion turbines 3786 may be mounted on the same shaft (not shown) and used to drive a generator (not shown) to produce electricity. The first compressor turbine 3780 aspires a working gas and compresses the working gas under continuous evaporation of small droplets of vaporizable liquid (e.g., water) delivered by a vaporizable liquid delivery device 3704. The droplets are injected during air intake or during the course of compression so that they are compressed along with the working gas. Alternatively, the vaporizable liquid may be supplied via external tanks, as described above. The compressed gas is saturated with vapor after compression and delivered by conduit 3706 to the cooler-condenser 3781.

The compressed mixture then enters the cooler-condenser 3781, is cooled, and the majority of the vaporizable liquid is condensed. The condensed liquid, or condensate, is collected in conduit 3708. A pump 3783, which is coupled on conduit 3708, re-circulates the condensed liquid and the liquid is recycled for injection by device 3704 into the compressor 3780.

The compressed, dried working gas (dried mixture) is delivered by conduit 3710 to and passes through the second compressor 3784. In second compressor 3784, the working gas is further compressed without the addition of vaporizable liquid. The twice-compressed gas goes on through conduit 3712 to the combustion chamber 3785 where the twice-compressed working gas combines with fuel and combusts to produce hot exhaust gas. The hot gas is delivered by conduit 3714 to the expansion turbine 3786 where the gas is expanded to produce an expanded working gas. The expanded working gas leaves the expansion turbine 3786 through the exhaust outlet 3787 at a temperature of approximately 250° C.

FIG. 38 shows the thermodynamic process carried out by the system 3700 of FIG. 37. The aspired working gas (e.g., air) is compressed by compressor 3780 together with the liquid droplets (e.g., water) in a substantially isentropic manner (state change A→B). Then, the compressed working gas with the vaporized liquid is cooled in cooler-condenser 3781 under condensation of the vaporized liquid (state change B→C). The dried, compressed working is gas is further compressed (C→D) before fuel is burned and the working gas temperature rises (D→E). Expansion lowers both the working gas temperature as well as its pressure (ELF). The working gas leaves the expansion turbine 3786 at a temperature (at state F), which is higher than ambient temperature (state A) but still significantly below the typical exhaust temperatures of existing devices. By mixing with ambient air (or, in the case of a closed-cycle gas turbine arrangement, by a heat exchanger/cooler) the working gas cools down further to ambient temperature (F→A).

The theoretical thermodynamic efficiency for the described system 3700 with the temperatures indicated in FIG. 37 is around 60% while the thermodynamic efficiency for the optimum process would be around 70%. The efficiency difference is indicated in FIG. 38 by the two hatched or shaded areas. Omitting the recuperator adds the triangle below the cooling line F→A (mixing of the exhaust gas with ambient air) to the imperfectness by liquid condensation instead of an isothermal compression (area below the condensation and cooling line B→C). Taking into account the typical adiabatic and mechanical efficiencies of the used compressor and expansion turbines, a significant efficiency increase over other devices and systems is achieved.

14. Open-Cycle Gas Turbines with Recuperator Between Two Compression Turbines and Between Two Expansion Turbines

Referring to FIG. 39, an illustrative open-cycle gas turbine system 3900 with compression before and after the recuperator and two-staged expansion before and after the recuperator is presented. The efficiency of this system 3900 may reach approximately 60% when using turbines with high efficiency. This system 3900 performs well at lower compression and expansion ratios, typically total pressure ratios between approximately 4:1 and approximately 20:1 over both stages. FIG. 40 is a theoretical, schematic S-T diagram of the thermodynamic process carried out by the system shown in FIG. 39. The open-cycle gas turbine system includes first and second compressors 3940, 3942, a recuperator 3941, a combustion chamber 3943, and first and second expansion turbines 3944, 3945. The compressor and expansion turbines may be mounted on the same shaft 3947 and used to drive a generator 3948 to produce electricity.

The first compressor turbine 3940 aspires a working gas through inlet 3902 and compresses the working gas under continuous evaporation of small droplets of vaporizable liquid (e.g., water) delivered by vaporizable liquid delivery device 3904. The droplets are injected during air intake or during the course of compression so that they are compressed along with the working gas. The compressed gas is saturated with vapor after compression and delivered by conduit 3906 to the recuperator 3941. The compressed mixture passes through the recuperator 3941 and is heated by the hot gas from the first expansion turbine 3944. After the recuperator 3941, the conduit 3908 delivers the working gas (mixture) to the second compressor 3942 to further heat and compress the working gas (gas-vapor mixture).

The twice-compressed working gas is delivered by conduit 3910 to the combustion chamber 3943. In the combustion chamber 3943, the working fluid (e.g., gas-vapor mixture) combines with fuel and combusts to produce a hot exhaust gas. The hot exhaust gas is delivered by conduit 3912 to the first expansion turbine 3944 where the hot exhaust gas is expanded being delivered by conduit 3914 to through the recuperator 3941. After the recuperator 3942, the working gas is delivered by conduit 3916 to and expanded further by a second expansion turbine 3945 to the base or ambient pressure. The fully expanded mixture is discharged into the environment through exhaust outlet 3946.

15. Open-Cycle Gas Turbines for Waste Heat Recovery

Referring to FIG. 41, an illustrative open-cycle gas turbine system 4100 for waste heat recovery is presented. FIG. 42 is a theoretical, schematic S-T diagram of the thermodynamic process carried out by the system 4100 shown in FIG. 41. The open-cycle turbine system 4100 is for recovering waste heat, such as recovering heat at approximately 400° C. from an internal combustion engine or the like. The system 4100 includes a compressor 4160, a heat exchanger 4161, an expansion turbine 4162, and an optional cooler-condenser 4163 for liquid recovery. The compressor turbine 4160 aspires a working gas at inlet 4102 and compresses the working gas with the evaporation of a vaporizable liquid, such as water delivered by vaporizable liquid delivery device 4104. The compression process may occur under continuous evaporation of small droplets of vaporizable liquid delivered by device 4104. The droplets are injected into the working gas during intake or during the course of compression so that they are compressed along with the working gas, as described above. Vaporizable liquid may also be supplied via external tanks as described above. The compressed working gas is substantially saturated with steam after compression and delivered by conduit 4106 to the heat exchanger 4161.

The compressed working gas (mixture) is heated in the heat exchanger 4161, using the waste heat source, before expansion by the expansion turbine 4162. A waste heat delivery conduit 4165 delivers waste heat to the heat exchanger 4161. Conduit 4166 removes the waste heat after it has passed through heat exchanger 4161 and provided thermal energy thereto. The expanded working gas exiting expansion turbine 4162 may optionally enter the cooler-condenser 4163 to be cooled, condensing the majority of the vaporizable liquid. The vaporizable liquid may enter conduit 4108. A pump 4110 on conduit 4108 re-circulates the condensed liquid to device 4104 so that the liquid can be re-injected into the compressor 4160. The expanded working gas exits the system 4100 through outlet 4164.

16. Open-Cycle Gas Turbines Directly Aspiring Hot Gases with Waste Heat Recovery with Initial Expansion to Low Temperature

Referring now to FIG. 43, an illustrative open-cycle gas turbine system 4310 for waste heat recovery is presented. FIG. 44 is a theoretical, schematic S-T diagram of the thermodynamic process carried out by the system 4310 shown in FIG. 43. The turbine system 4310 for recovering waste heat includes an expansion turbine 4300, a compressor 4302, and an optional cooler-condenser 4304. The expansion turbine 4300 and the compressor 4302 may be mounted on the same shaft 4305 to drive a generator 4306.

The expansion turbine 4300 aspires waste heat gas through inlet 4301 and expands the gas to a low temperature and a pressure well below ambient pressure. For example, in FIG. 43, the temperature after expansion in the expansion turbine 4300 is approximately 80° C. and the pressure is approximately one tenth of ambient pressure. The expanded waste heat gas is delivered by conduit 4312 to the compressor 4302.

The compressor turbine 4302 compresses the expanded waste heat gas with the evaporation of a vaporizable liquid provided by vaporizable liquid delivery device 4308. The compression process may occur under continuous evaporation of small droplets of vaporizable liquid. The droplets are injected into the gas during intake or during the course of compression so that they are compressed along with the gas as discussed herein. Vaporizable liquid may also be supplied via external tanks as described above. The compressed gas is substantially saturated with steam after compression and is delivered by conduit 4316 to optional cooler-condenser 4304 before exiting the system 4310 through outlet 4303. The optional cooler-condenser 4304 may receive the gas and cool and condense the majority of the vaporizable liquid. A pump (not shown) re-circulates the condensed liquid collected by conduit 4318 so that the liquid can be injected into the compressor 4302.

17. Open-Cycle Gas Turbines for Waste Heat Recovery with Initial Expansion to Moderate Temperature

Referring to FIG. 45, an illustrative turbine system 4500 for recovering waste heat includes an expansion turbine 4520 connected to a compressor 4523 by a conduit 4522 and an optional cooler-condenser 4525. The compressor turbine 4523 and the expansion turbine 4520 may be mounted on the same shaft (not shown). FIG. 46 is a theoretical, schematic S-T diagram of the thermodynamic process carried out by the system 4500 shown in FIG. 45. The expansion turbine 4520 aspires waste heat gas through inlet 4521 and expands the gas to a moderate temperature, for example, 150° C. The temperature to which the waste heat gas is expanded is determined based on the actual mechanical efficiencies of the particular compression turbine and expansion turbines used.

Vaporizable liquid droplets are injected by a first vaporizable liquid delivery device 4502 into the conduit 4522 between the expansion turbine 4520 and the compressor 4523. The conduit 4522 is formed so that the transit time of the droplets is long enough to allow vaporization. For example in one illustrative embodiment, the length of conduit 4522 allows for between approximately 0.2 and 1.0 seconds of transit time. The volume of the conduit 4522 is approximately equal to between 20% and 100% of the volume of working gas at the predicted pressure and temperature which passes a point within one second. The compressor turbine 4523 compresses the gas with the evaporation of additional vaporizable liquid. Additional vaporizable liquid is delivered to the compressor 4523 by a second vaporizable liquid delivery device 4504. The compression process may occur under continuous evaporation of small droplets of vaporizable liquid. The droplets are injected into the air during intake or during the course of compression so that they are compressed along with the waste heat gas. Vaporizable liquid may also be supplied via external tanks as described above. The compressed waste heat gas is substantially saturated with steam after compression.

The compressed waste heat gas (mixture) may optionally enter the cooler-condenser 4525 to be cooled. Coding the gas condenses the majority of the vaporizable liquid, which is delivered to conduit 4506. A pump (not shown) re-circulates the condensed liquid so that the liquid can be injected into the compressor 4523 by device 4504 and the conduit 4522 by the device 4502.

18. Open-Cycle Piston Compressor and Expansion Turbine

Referring to FIG. 47, a schematic diagram of an illustrative open-cycle, combined piston compressor/expansion turbine system 4710 is presented. This system 4710 may be particularly efficient for power turbines producing less than about 50 kW up to around 1 MW. An open-cycle piston compressor-expansion turbine system 4710 includes a screw compressor 4700 having an internal compression space of a predetermined volume, a recuperator 4701, a combustion chamber 4702, or high temperature heat exchanger to provide external thermal energy, coupled shafts 4705, and an expansion turbine 4703.

The screw compressor 4700 aspires a working gas, e.g., ambient air, through inlet 4712 and compresses the working gas with the evaporation of vaporizable liquid provided by vaporizable liquid delivery device 4714. The compression process may occur under continuous evaporation of small droplets of vaporizable liquid (e.g., water) from device 4714. The droplets are injected into the working gas during intake or during the course of compression so that they are compressed along with the working gas. Vaporizable liquid may also be supplied via external tanks as described above. The compressed working gas is substantially saturated with vapor after compression and is delivered by conduit 4716 to the recuperator 4701.

The compressed working gas (mixture) enters the recuperator 4701 where the compressed working gas is heated by the hot exhaust gas from the expansion turbine 4703. The heated, compressed working gas leaves the recuperator 4701 and is delivered by conduit 4718 to the combustion chamber 4702. In the combustion chamber 4702, fuel is burned with the working gas to create an exhaust gas. The exhaust gas leaves the combustion chamber 4702 through conduit 4720 and enters the expansion turbine 4703 where the expanded exhaust gas is expanded. The expanded exhaust gas is supplied to the recuperator 4701 by conduit 4722 where the expanded exhaust gas heats the compressed working gas from the compressor 4700. The exhaust gas then exits the system 4710 through exhaust outlet 4704.

The expansion turbine 4703 drives the screw compressor 4700 through coupled shafts 4705 where a gear 4724 balances the rotation speed of the turbine with that of the screw compressor. A generator 4706 is coupled to the expansion turbine 4703 to generate electricity.

19. Open-Cycle Gas Turbine System for Cooling

Referring to FIG. 48, a schematic diagram of an illustrative open-cycle gas turbine system 4800 for generating a cold working gas for cooling is presented. The system 4800 may be used to liquefy gas, for example natural gas, or other cooling applications, such as flash freezing food. The open-cycle gas turbine system 4800 for cooling includes a compressor turbine 4820, a recuperator 4821, a combustion chamber 4822, a first expansion turbine 4823, a cooler-condenser 4824, a second expansion turbine 4826, a shaft 4829, and a low temperature heat exchanger 4827.

The compressor turbine 4820 aspires a working gas through inlet 4802 at ambient pressure and temperature and compresses the working gas under continuous vaporization of vaporizable liquid, for example under continuous evaporation of small droplets of vaporizable liquid. The vaporizable liquid is provided by vaporizable liquid delivery device 4804. The droplets may be injected into the working gas during intake or during the course of compression so that they are compressed along with the working gas. Vaporizable liquid may also be supplied via external tanks as described herein. If the critical temperature of the working gas is lower than the critical temperature of the gas to be liquefied, the vaporizable liquid may also be supplied at a raised temperature and pressure as described above. The compressed gas is substantially saturated with vapor after compression and delivered by conduit 4806 to the recuperator 4821.

After compression, the compressed working gas (gas-vapor mixture) enters the recuperator 4821 where the compressed working gas is heated by the hot exhaust gas from the first expansion turbine 4823. After leaving the recuperator 4821, the heated working gas is delivered by conduit 4808 to the combustion chamber 4822 where the working gas fuel is burned and the working gas temperature rises. The fuel may include hydrocarbons produced at the liquid natural gas production site or any suitable fuel. The combustion chamber 4822 thus produces an exhaust gas that is delivered by conduit 4810 to the first expansion turbine 4823.

The heated exhaust gas expands in the first expansion turbine 4823 to an intermediate pressure above ambient pressure and is supplied by conduit 4812 to the recuperator 4821 to heat the compressed working gas from the compressor turbine 4820. Consequently, the expanded exhaust gas temperature decreases. The expanded exhaust gas is then delivered by conduit 4814 to the cooler-condenser 4824.

In the cooler-condenser 4824, the expanded exhaust gas is further cooled to ambient temperature and the vaporized liquid condenses and thereby produces a dried exhaust gas, or dried working gas. The liquid is re-circulated through a conduit 4825 to the vaporizable liquid delivery device 4804 associated with compressor turbine 4820.

The dried working gas is delivered by conduit 4816 to the second expansion turbine 4826. In the second expansion turbine 4826, the dried working gas is expanded to the base pressure of the system, i.e., ambient pressure, to produce a cold working gas. All turbines are preferably mounted on the same shaft 4829.

Because the working gas temperature at the beginning of the second expansion is ambient temperature, the second expansion decreases the working gas temperature far below ambient temperature and to a temperature low enough to liquefy a liquefiable gas, e.g., natural gas, or other gases with a similar critical temperature, such as ethane and carbon dioxide.

The cold working gas is delivered by conduit 4818 to the low temperature heat exchanger 4827 where the cold working gas cools pressurized liquefiable gas (e.g., natural gas) down to the temperature where working gas saturation pressure reaches ambient pressure. Then, the working gas is discharged into the environment through the exhaust outlet 4828. The pressurized liquefiable gas is supplied through the inlet 4830 and may leave the low temperature heat exchanger 4827 through outlet 4831 at a temperature of around −160° C. for natural gas and a vapor pressure approximately equal to the ambient pressure (around 1 bar). In the example of natural gas, liquid natural gas (LNG) leaves through the outlet 4831.

20. Open-Cycle Gas Turbine System with Combined External and Internal Combustion

Referring to FIG. 49, a schematic diagram of an illustrative open-cycle gas turbine system 4900 with external and internal combustion is presented. FIG. 50 is a theoretical, schematic S-T diagram of the thermodynamic process carried out by the in the system 4900 of FIG. 49. The open-cycle gas turbine system 4900 with external and internal combustion includes an external combustion subsystem 4902 and an internal combustion subsystem 4904. The external combustion subsystem 4904 includes a low temperature furnace 4940, a high temperature furnace 4941, a high temperature heat exchanger 4942, and an auxiliary compressor 4944. The internal combustion subsystem 4904 includes a compressor turbine 4943, a combustion chamber 4945, and an expansion turbine 4946. The open-cycle gas turbine system 4900 of FIG. 49 may also split the expanded working gas into two streams with splitter 5148 and use an additional heat exchanger 5102 as shown in FIG. 51.

Referring again to FIG. 49, the external combustion subsystem 4902 generates heat from solid fuel, such as biomass and including wood. The solid fuel undergoes partial pyrolysis in the low temperature furnace 4940, which vaporizes clean and light molecules and produces steam and light hydrocarbons. Pyrolysis starts at around 150° C. for typical biomass with high hydrogen content. The thermal energy for the partial pyrolysis may be extracted from the hot exhaust gas in conduit 4906 for this embodiment. The hot exhaust gas in conduit 4906 from the internal combustion subsystem 4904 has been through the high temperature furnace 4941. Alternatively, the hot exhaust gas in conduit 4906 may arrive at the low temperature furnace 4940 directly from the expansion turbine 4946. Other low temperature thermal energy sources, such as the waste heat of other engines or medium-temperature geothermal sources, may also be used to provide heat for the partial pyrolysis process in low temperature furnace 4940.

The gas products of the partial pyrolysis are extracted through conduit 4908 from the low temperature furnace 4940 and compressed by an auxiliary compressor 4944. After compression to a predetermined pressure equal to the end pressure of the compressor turbine 4943, the gas products are transferred by conduit 4910 to the combustion chamber 4945 for internal combustion.

After partial pyrolysis in the low temperature furnace 4940, the solid fuel, e.g., biomass, that has not yet pyrolyzed is moved into the high temperature furnace 4941 to be burned with air. The remaining solid fuel is burned in the high temperature furnace 4941 to produce flue gases which in turn heat the compressed working gas from the compressor turbine 4943 through the high temperature heat exchanger 4942. In some cases the exhaust from the expansion turbine 4946 provides sufficient oxygen for combustion and may be utilized. In some cases, additional ambient air is supplied to the high temperature furnace 4941 for combustion with the remaining solid fuel. The high temperature heat exchanger 4942 may form an integral part of the high temperature furnace 4941. The flue gases may also transfer thermal energy to the solid fuel in the low temperature furnace 4940 for the partial pyrolysis process.

The internal combustion subsystem 4904 is an internally fired gas turbine system. The compressor turbine 4943 aspires a working gas, e.g., ambient air, through inlet 4912 and compresses the working gas with the evaporation of a vaporizable liquid provided by vaporizable liquid delivery device 4914. The compression process may occur under continuous evaporation of small droplets of vaporizable liquid. The droplets may be injected during intake or during the course of compression and are compressed along with the working gas. Vaporizable liquid may also be supplied via external tanks as described above. The vaporizable liquid may be supplied at a raised temperature and pressure as described above. After compression, the working gas (gas-vapor mixture) is delivered by conduit 4916 to the high temperature heat exchanger 4942 which, in turn, is heated by the hot flue gases from the high temperature furnace 4941 and exhaust gas from the expansion turbine 4946. Then, the compressed working gas is delivered by conduit 4918 to the combustion chamber 4945.

In the combustion chamber, the light and clean pyrolysis gas from the low temperature furnace 4940, which has been compressed to combustion chamber pressure by the auxiliary compressor 4944 and delivered by conduit 4910, is burned to produce an exhaust gas. The working gas temperature rises again to approximately 1100° C. (state change C→D in FIG. 50). The exhaust gas is delivered by conduit 4920 from the combustion chamber 4945 to the expansion turbine 4946.

In the expansion turbine 4946, the exhaust gas is expanded to around 400° C. and ambient pressure (state change D→E in FIG. 50). With a working gas of air, the expanded exhaust gas remains mainly composed of air with its natural oxygen content, since a minority of the oxygen in the air is consumed by combustion in the combustion chamber 4945. The expanded exhaust gas then enters conduit 4906.

Then, the expanded exhaust gas flows to the high temperature furnace 4941 where the expanded exhaust gas provides heat to the solid fuel remaining after partial pyrolysis, and thereby helps increase the temperature of the exhaust gas to about 700° C. or more (state change ELF in FIG. 50). The exhaust gas transfers additional thermal energy in the high temperature heat exchanger 4942 to the freshly compressed working gas from the compressor turbine 4943 (state change F→G in FIG. 50).

Afterwards the exhaust gas enters the low temperature furnace 4940 to transfer more thermal energy to the solid fuel to effect the partial pyrolysis described above and the exhaust gas temperature further decreases (state change G→H in FIG. 50). Finally, the exhaust gas is discharged through the exhaust outlet 4947 into the environment where they cool down to the dew point (state change H→I in FIG. 50) and finally the vapor condenses (state change I→A in FIG. 50) or is diluted in the ambient air.

B. Closed-Cycle Gas Turbines

1. Closed-Cycle Gas Turbines with Recuperator and No Co-Generation of Heat and Power

Referring to FIG. 52, an illustrative closed-cycle gas turbine system 5200 is presented. FIG. 53 is a theoretical, schematic S-T diagram of the thermodynamic process for the system 5200 shown in FIG. 52. The closed-cycle gas turbine system 5200 includes a compressor turbine 5270, a heat exchanger 5272 to provide external thermal energy, a recuperator 5271, an expansion turbine 5273, and a cooler-condenser 5274 in a closed system. The compressor turbine 5270 and the expansion turbine 5273 may be mounted on the same shaft (not shown).

The compressor turbine 5270 aspires a working gas and compresses the working gas with the evaporation of a vaporizable liquid provided by vaporizable delivery device 5202. The compression process may occur under continuous evaporation of small droplets of vaporizable liquid. The droplets may be injected during intake or during the course of compression so that they are compressed along with the working gas. Vaporizable liquid may also be supplied via external tanks as described above. The external tanks effectively replace external intercoolers. Vaporizable liquid may also be supplied at a raised temperature and pressure as described above. The compressed working gas is substantially saturated with vapor after compression and is delivered by conduit 5204 to the recuperator 5271.

The compressed working gas then enters the recuperator 5271 where the working gas is heated by the hot exhaust gas from the expansion turbine 5273. The heated and compressed working gas mixture leaves the recuperator 5271 and enters via conduit 5206 the high temperature heat exchanger 5272. The hot working gas leaves the high temperature heat exchanger 5272 through conduit 5208 and enters the expansion turbine 5273 where hot working gas is expanded. The expanded working gas is supplied by conduit 5210 to the recuperator 5271 where expanded working gas heats the compressed working gas from the compressor turbine 5270 and whereby the expanded working gas is cooled.

The cooled working gas is then delivered by conduit 5212 to the cooler-condenser 5274 and is passed through the cooler-condenser 5274 to remove (condense) the liquid vaporized during compression and heat. The removed liquid, or condensate, is delivered to conduit 5275, which includes pump 5276. A pump 5276 re-circulates the condensed liquid so that the liquid can be injected into the compressor 5270 by device 5202. The cooled and dry working gas is delivered by conduit 5214 to the compressor 5270 and is re-circulated through the system 5200.

The shaded area in FIG. 53 is the mechanical power which—in theory—can be still obtained from the condensing vapor in the exhaust gas. As is apparent, this “wasted” power is relatively low because the dew point (where condensation starts) is low after expansion (large volume low vapor density low dew point) and, hence, the energy content of the (quite large) energy carried away is low, promoting a high overall efficiency.

2. Closed-Cycle Gas Turbines with Recuperator, CO₂ Working Gas and CO₂ Sequestration at Low Pressure Without Co-Generation of Heat and Power

Referring to FIG. 54, an illustrative closed-cycle gas turbine system 5410 with carbon dioxide (CO₂) sequestration by liquefaction using oxygen or liquid natural gas as the cooling agent is provided. The closed-cycle gas turbine system 5410 includes a compressor turbine 5400, a recuperator 5402, a combustion chamber 5403, an expansion turbine 5404, and a cooler-condenser 5405 in a closed system.

The compressor turbine 5400 aspires CO₂ and compresses the CO₂ with the evaporation of water. The compression process may occur under continuous evaporation of small droplets of water provided by vaporizable liquid delivery device 5412. The droplets may be injected during intake or during the course of compression so that they are compressed along with the CO₂. Water may also be supplied via external tanks as described above. The external tanks effectively replace external intercoolers. Water may also be supplied at a raised temperature and pressure as described above. The compressed CO₂ is substantially saturated with water vapor after compression and is delivered by conduit 5414 to low temperature heat exchanger 5401. The optional low temperature heat exchanger 5401 removes condensate to prepare a dry compressed working gas of CO₂. The condensate is received in conduit 5416, which may include pump 5418 to circulate the condensate back to vaporizable liquid delivery device 5412. The compressed working gas leaves the low temperature heat exchanger 5401 and is delivered by conduit 5420 to the recuperator 5402.

The compressed working gas then enters the recuperator 5402 where the gas is heated by the hot exhaust gas from the expansion turbine 5404. The heated, compressed working gas mixture leaves the recuperator 5402 via conduit 5422 and enters the combustion chamber 5403 where a hydrocarbon fuel, such as liquid natural gas, is introduced at inlet 5424 and burned with highly oxygen enriched air or pure oxygen delivered through inlet 5426. Some arrangements may use O₂ enrichment devices to increase the O₂ in the aspired air up to an approximately 85% or 90% share, for example zeolith filters, membrane filters, or the like. The hot exhaust gas, still a mixture of CO₂ and water, leaves the combustion chamber 5403 via conduit 5428 and enters the expansion turbine 5404 where the exhaust gas is expanded.

The expanded exhaust gas is supplied to the recuperator 5402 where the exhaust gas heats the compressed working gas from the compressor turbine 5400. The cooled exhaust gas is then delivered by conduit 5430 to and passed through a cooler-condenser 405 to remove the liquid (condensate). A conduit 5432 and pump 5408 re-circulate a portion of the condensed water so that the water can be injected into the compressor 5400. Water not required by the system is discharged through outlet 5409. The CO₂ produced in the combustion chamber 5403 and cooled in cooler-condenser 5405 is separated and channeled via a valve 5406 to conduit 5436, which may go to a liquefaction engine (see, FIG. 55) for liquefying and storage of any surplus CO₂. The cooled and dry CO₂ is re-circulated via conduit 5438 to the compressor 5400.

Referring to FIG. 55, an illustrative liquefaction system 5500, which may be employed with the arrangement shown in FIG. 54, is presented. The liquefaction system 5500 includes a cooler 5511 and a condenser/evaporator 5512 for liquefying a liquefiable gas in conduit 5510 are coupled to a closed-cycle low temperature steam engine 5502. The closed-cycle low temperature steam engine 5502 includes an expansion device or expansion turbine 5514, a second condenser/evaporator 5515 and a pump 5516. The expansion device 5514 in the low temperature vapor engine drives a generator 5518 to produce electricity.

The CO₂ produced in system 5400 (FIG. 54) is channeled to the liquefaction engine through conduit 5436 is delivered to conduit 5510 (FIG. 55) and is cooled in the cooler 5511 to produce a saturated mixture of gas and vapor CO₂. Then, the saturated CO₂ gas passes through the condenser/evaporator 5512 where the thermal energy released from condensing the CO₂ is used to vaporize the working fluid of the low temperature steam engine 5502. The working fluid may be liquid natural gas. The vaporization of the working fluid of the low temperature vapor engine 5502 causes the CO₂ to condense. When liquid natural gas is used as the working fluid, the vaporization energy of the working fluid is sufficient to condense substantially all of the CO₂ produced by burning liquid natural gas in the gas turbine 5400 of FIG. 54. In one illustrative embodiment, the CO₂ produced by burning HC in the combustion chamber 5403 of FIG. 54 is channeled to the above described liquefying engine shown in FIG. 55. In other words, no additional cryogenic device may be required, since cooling by the vaporization of liquid natural gas alone is sufficient to condense all of the CO₂ produced by combustion of the same amount of natural gas. Using the closed-cycle low temperature steam engine of FIG. 55 preferably condenses substantially all of the CO₂.

The vapor produced from the low temperature working fluid is used to drive the expansion device 5514 of the low temperature steam engine to produce mechanical energy. The vaporized working fluid of the low temperature steam engine may be condensed in the second condenser-evaporator 5515 by transferring its thermal energy in order to vaporize liquid natural gas or O₂ to be used in the combustion chamber 5403. The vaporized liquid natural gas or O₂ enters at inlet 5517. The vaporized liquid natural gas or O₂ may also be used in the cooler to cool the CO₂ produced in the combustion chamber 5403 when the CO₂ first enters the liquefaction engine.

3. Closed-Cycle Gas Turbines with Recuperator with CO₂ Working Gas and Sequestration at High Pressure without Co-Generation of Heat and Power

Referring to FIG. 56, an illustrative closed-cycle gas turbine system 5600 with carbon dioxide sequestration by extraction at the upper pressure level of the closed-cycle system. The closed-cycle gas turbine system 5600 includes a compressor turbine 5620, an extraction valve 5622, a recuperator 5623, a combustion chamber 5624, an expansion turbine 5625, and a cooler-condenser 5626 in a closed system.

The compressor turbine 5620 aspires carbon dioxide CO₂ through inlet 5602 at a predetermined base pressure and compresses CO₂ to an upper pressure that is high enough to allow condensation of CO₂ at typical environmental temperatures, e.g., between 0° C. and 25° C. Thus, no cryogenic device is required. The compressor compresses the CO₂ with the evaporation of water provided by vaporizable liquid delivery device 5604. The compression process may occur under continuous evaporation of small droplets of water. The droplets may be injected during intake or during the course of compression so that they are compressed along with the CO₂. Water may also be supplied via external tanks as described above. The external tanks effectively replace external intercoolers. Water may also be supplied at a raised temperature and pressure as described above. The compressed CO₂ is substantially saturated with water vapor after compression and delivered to optional low temperature heat exchanger 5621 by conduit 5608, which removes condensate 5609.

The CO₂ leaving exchanger 5621 is delivered by conduit 5610 to separation valve or extraction valve 5622. Then a portion of the CO₂ equal to that produced in the combustion chamber 5624 on each cycle is separated from the compressed and saturated CO₂ and channeled via the extraction valve 5622 and conduit 5612 for transport or storage.

The remaining compressed working gas (CO₂ mixture) then enters the recuperator 5623 via conduit 5614 where the compressed working gas is heated by the hot exhaust gas from the expansion turbine 5625. The heated, compressed working gas mixture leaves the recuperator 5623 via conduit 5616 and enters the combustion chamber 5624 where a hydrocarbon fuel 5618 is burned with pure oxygen 5628. The hot exhaust gas, still a mixture of CO₂ and water, leaves the combustion chamber 5624 via conduit 5630 and enters the expansion turbine 5625 where the exhaust gas is expanded. The expanded gas is supplied via conduit 5632 to the recuperator 5623 where the expanded exhaust gas heats the compressed working fluid mixture. The cooled expanded exhaust gas is then passed via conduit 5634 through a cooler-condenser 5626 to remove liquid. A pump 5636 and conduit 5638 re-circulates a portion of the condensed water so that the water can be injected into the compressor 5620. Water not required by the system is discharged at outlet 5640. The cooled and dry CO₂ is re-circulated through the system 5600, starting with the compressor 5620.

4. Closed-Cycle Gas Turbines with AR/CO₂ Working Gas and Sequestration at Low Pressure without Co-Generation of Heat and Power

Referring to FIG. 57, an illustrative closed-cycle gas turbine system 5700 with carbon dioxide sequestration by liquefaction is presented. The closed-cycle gas turbine system 5700 utilizes using a mixture of CO₂ and a gas with a high isentropic exponent, such as Ar, He, or N₂ as the working gas with a recuperator and without co-generation of heat and power. The system 5700 includes a compressor turbine 5740, a recuperator 5741, a combustion chamber 5742, first and second expansion turbines 5743, 5744, a cooler-condenser 5745, and an extraction valve 5748 in a closed system. If helium is used as part of the working gas, Helium has a high thermal transfer rate, so smaller heat exchangers are needed, but have a low molecular weight, so turbines must rotate at higher speeds.

The compressor turbine 5740 aspires the working gas through inlet 5702 and compresses the working gas under continuous evaporation of small droplets of water provided by vaporizable liquid delivery device 5704. The droplets are injected during intake or during the course of compression so that they are compressed along with the working gas. Water may also be supplied via external tanks as described above. The external tanks effectively replace external intercoolers. Water may also be supplied at a raised temperature and pressure as described above. The compressed working gas is saturated with water vapor after compression.

The compressed working gas then, via conduit 5706, enters the recuperator 5741 where the working gas is heated by the hot exhaust gas from the first expansion turbine 5743. The heated, compressed working gas mixture leaves the recuperator 5741 and, via conduit 5708, enters the combustion chamber 5742 where a hydrocarbon fuel 5710 is burned with pure oxygen 5712. The combustion produces CO₂ and water. The hot exhaust gas leaves the combustion chamber 5742 via conduit 5714 and enters the first expansion turbine 5743 where hot exhaust gas is expanded to an intermediate pressure. The partially expanded gas is supplied via conduit 5716 to the recuperator 5741 where exhaust gas heats the compressed working gas from the compressor turbine 5740.

The cooled exhaust gas is then passed via conduit 5718 through the second expansion turbine 5744 where exhaust gas is expanded further to the base pressure of the system 5700. Then, the twice-expanded exhaust gas is passed via conduit 5720 through a cooler-condenser 5745 to remove liquid. A pump 5750 and conduit 5722 re-circulates a portion of the condensed water so that the water can be injected by device 5704 into the compressor 5740. Water not required by the system may be discharged by outlet 5724.

After the cooler-condenser 5745, the twice-expanded working gas enters the extraction valve 5748 via conduit 5726 where a sequestration portion of the working gas containing the CO₂ produced in the combustion chamber 5742 is separated and channeled via a valve to a liquefaction engine. Extracting at the upper pressure of the system 5700 allows liquefaction at or near ambient pressure without the use of another compressor external to the system. The liquefaction engine for liquefying removes the CO₂ and returns, via valve 5749, the gas with a high isentropic exponent to the closed-cycle gas turbine to be mixed with the working portion of the working gas. The gas with a high isentropic exponent is re-circulated via conduit 5728 through the system 5700, starting with the compressor 5740. The compressor 5740 and expansion turbines 5743, 5744 may be on a common shaft 5746. The shaft 5746 may provide energy to a generator 5747 to produce electricity.

Referring now to FIG. 58, a liquefying engine which may be employed with the arrangement shown in FIG. 57 is presented. The liquefying engine 5800 includes a cooler 5861, a CO₂ condenser 5862, and a separator 5863. The sequestration portion in conduit 5860 is first cooled in the cooler 5861 then substantially all of the CO₂ is condensed in the condenser 5862 before separation by separator 5863 from the gas with a high isentropic exponent. The cooled gas with a high isentropic exponent returns via conduit 5865 to the closed-cycle gas turbine via the cooler 5861, and thereby extracts thermal energy from the sequestration portion.

5. Closed-Cycle Gas Turbines with AR/CO₂ Working Gas and Sequestration by Extraction

Referring not to FIG. 59, an illustrative closed-cycle gas turbine system 5900 with carbon dioxide sequestration by extraction at the upper pressure level of the closed-cycle system is presented. The closed-cycle gas turbine system 5900 preferably uses a mixture of CO₂ and a gas with a high isentropic exponent, such as Ar, He, or N₂ as the working gas with recuperator and without co-generation of heat and power. The system 5900 includes a compressor turbine 5980, an extraction valve 5988, a heat exchanger 5990, a CO₂ condenser 5991, a return mixer 5989, a recuperator 5981, a combustion chamber 5982, first and second expansion turbines 5983, 5984, and a cooler-condenser 5995 in a closed system. If helium is used, helium has a high thermal transfer rate, and so smaller heat exchangers are needed, but because helium has a low molecular weight, the turbines must rotate at higher speeds.

The compressor turbine 5980 aspires the working gas through inlet 5902 and compresses the working gas under continuous evaporation of small droplets of water provided by vaporizable liquid delivery device 5904. The droplets are injected during intake or during the course of compression so that they are compressed along with the working gas. Water may also be supplied via external tanks as described above. The external tanks effectively replace external intercoolers. Water may also be supplied at a raised temperature and pressure as described above. The compressed working gas is saturated with water vapor after compression and is delivered by conduit 5906 to an extraction valve 5988. At the extraction valve 5988, argon/CO₂ or other desired sequestration gas is removed by the extraction valve 5988 and delivered to conduit 5908. Preferably the sequester position in conduit 5908 is the CO₂ produced in the combustion chamber 5982, which is described below.

The sequestration portion is cooled in a heat exchanger 5990. Then substantially all of the CO₂ is condensed in the condenser 5991 with separation from the gas with a high isentropic exponent. The cooled gas with a high isentropic exponent returns through conduit 5910 via the heat exchanger 5990 thereby extracting thermal energy from the sequestration portion. The gas with a high isentropic exponent is mixed with the working gas in the closed-cycle gas turbine via the return mixer 5989 and is re-circulated through the system 5900. The non-sequestered portion from conduit 5912 of the compressed working gas and the gas returned in conduit 5910 are delivered by conduit 5914 to the recuperator 5981.

The working gas then enters the recuperator (i.e., a heat exchanger for “recouping” the heat from the exhaust gases) 5981 where working gas is heated by the hot exhaust gas from the expansion turbine 5983. The heated, compressed working gas mixture leaves the recuperator 5981 and via conduit 5916 enters the combustion chamber 5982 where a hydrocarbon fuel 5918 is burned with pure oxygen 5920 to produce a mixture of CO₂ and water. The hot exhaust gas leaves the combustion chamber 5982 and via conduit 5922 enters the first expansion turbine 5983 where the exhaust gas is expanded to an intermediate pressure.

The expanded exhaust gas is supplied via conduit 5924 to the recuperator 5981 where the expanded exhaust gas heats the compressed working gas. After the recuperator 5981 the exhaust gas is delivered via conduit 5926 to and expanded further by a second expansion turbine 5984 to produce a twice-expanded exhaust gas at the base or ambient pressure. The twice-expanded exhaust gas is then passed by conduit 5928 through a cooler-condenser 5985 to remove liquid. The liquid, or condensate, is delivered to conduit 5930. A pump 5992 on conduit 5930 re-circulates a portion of the condensed water so that the water can be injected into the compressor 5980 by device 5904. Water not required by the system is discharged by outlet 5932. The cooled and dry CO₂ exiting cooler-condenser 5985 is re-circulated via conduit 5932 through the system 5900, starting with the compressor 5980.

6. A Closed-Cycle Gas Turbine with Recuperator and Co-Generation of Heat and Power

Referring to FIG. 60, an illustrative closed-cycle gas turbine system 6000 with CHP in which the thermal energy for CHP is extracted immediately after compression when the dew point is higher due to the increased density of the working gas after compression is presented. FIGS. 17 a, 17 b, and 17 c show the thermodynamic cycle carried out by the system 6000 shown in FIG. 60 during maximum heat production, maximum electricity production, and mixed heat and electricity production, respectively. The amount of thermal energy extracted from the system 6000 may be varied dynamically according to the actual requirements of the external consumer (e.g., building heating).

Both heat and power can be produced independently by the same system with minor variations in the thermal efficiency of the system. For example, at full thermal load, the power producing efficiency may be approximately 50% using the optimum thermal cycle as indicated by the cross-hatched portion of FIG. 17 a. When producing power only (no heat), the system efficiency may be approximately 53% using the optimum thermal cycle as indicated by the cross-hatched portion of FIG. 17 b. At approximately 50% of full heat load, then the power production efficiency may be approximately 51.5% using the optimum thermal cycle as indicated by the cross-hatched portion of FIG. 17 c. The electricity produced also varies with the power production efficiency but can be kept constant by burning slightly more fuel.

The system 6000 includes a compressor turbine 6080, a low temperature heat exchanger 6081, a recuperator 6082, a high temperature heat exchanger 6083, an expansion turbine 6084, and a cooler-condenser 6085 in a closed system. The compressor turbine 6080 aspires a working gas at inlet 6002 and compresses the working gas under continuous evaporation of small droplets of vaporizable liquid (e.g., water) provided by vaporizable liquid delivery device 6004. The droplets are injected during intake or during the course of compression so that they are compressed along with the air. Water may also be supplied via external tanks as described above. The external tanks effectively replace external intercoolers. Water may also be supplied at a raised temperature and pressure as described above. The compressed gas is saturated with vapor after compression and delivered by conduit 6006 to the low temperature heat exchanger 6089.

The compressed working gas then enters the low temperature heat exchanger 6081 to be cooled and the vaporizable liquid condenses and extracts a portion of the thermal energy in the working gas. The condensed liquid, or condensate, may be recycled via conduit 6088 and the feed pump 6089 by injecting the condensate into the compressor 6080 with device 6004. Then, the colder and drier working gas flows via conduit 6008 to the recuperator 6082 where the compressed working gas is heated by the hot exhaust gas from the expansion turbine 6084. The heated, compressed working gas mixture leaves the recuperator 6082 via conduit 6010 and enters the high temperature heat exchanger 6083.

The hot working gas leaves the high temperature heat exchanger 6083 via conduit 6012 and enters the expansion turbine 6084 where the working gas is expanded. The expanded working gas is supplied to the recuperator 6083 where the working gas heats the compressed working gas from the compressor turbine 6080. The cooled working gas is then passed via conduit 6014 through a cooler-condenser 6085 to remove additional liquid, or condensate, and heat. The condensate is delivered to conduit 6086. A pump 6087 on conduit 6086 re-circulates the condensed liquid so that the liquid can be injected by device 6004 into the compressor 6080. The cooled and dry gas exits the cooler-condenser 6085 through conduit 6016 is re-circulated through the system 6000, starting with the compressor 6080.

7. Closed-Cycle Gas Turbines with Recuperator with CO₂ Working Gas and Sequestration with Co-Generation of Heat and Power

Referring to FIG. 61, an illustrative closed-cycle gas turbine system 6110 with CHP and carbon dioxide sequestration by liquefaction is presented. While CO₂ is mentioned here and in other embodiments, it should be understood that other desired sequestration gases might desired and produced. The closed-cycle gas turbine system 6110 preferably uses CO₂ as the working gas with a recuperator and co-generation of heat and power. The system 6110 includes a compressor turbine 6100, a low temperature heat exchanger 6101, a recuperator 6102, a combustion chamber 6103, an expansion turbine 6104, and a cooler-condenser 6105 in a closed system.

The compressor turbine 6100 aspires CO₂ at inlet 6112 and compresses the working gas (CO₂) under continuous evaporation of small droplets of water provided by vaporizable liquid delivery device 6114. The droplets are injected upon intake or in the course of compression so that they are compressed along with the CO₂. Water may also be supplied via external tanks as described above. The external tanks effectively replace external intercoolers. Water may also be supplied at a raised temperature and pressure as described above. The compressed working gas (CO₂) is saturated with vapor after compression and is delivered by conduit 6116 to the low temperature heat exchanger 6101.

The compressed working gas then enters the low temperature heat exchanger 6101 and is cooled and the water is condensed to extract a portion of the thermal energy in the mixture. The cooling is heat exchanger 6101 removes liquid, or condensate, which is delivered to conduit 6118, which has pump 6120. By adjusting the flow of the liquid in conduit 6118 carrying the thermal energy away from the working gas, the amount of heat produced for consumption can be varied. The compressed working gas then enters via conduit 6122 the recuperator 6102 (i.e., a heat exchanger for “recouping” the heat from the exhaust gases) where the compressed working gas is heated by the hot exhaust gases from the expansion turbine 6104. The heated, compressed working gas mixture leaves the recuperator via conduit 6124 and enters the combustion chamber 6103 where a hydrocarbon fuel 6126 and oxygen 6128 are supplied and burned. The exhaust gas, still a mixture of CO₂ and water, leaves the combustion chamber via conduit 6130 and enters the expansion turbine 6104 where the compressed working gas is expanded. The expanded working gas, or expanded exhaust gas, is supplied via conduit 6132 to the recuperator where the expanded working gas heats the compressed mixture from the compressor turbine 6100.

The cooled expanded exhaust gas is then passed via conduit 6134 through a cooler-condenser 6105 to remove liquid. The removed liquid is delivered to conduit 6136, which has pump 6138. Pumps 6138, 6120 re-circulate a portion of the condensed water so that the water can be injected into the compressor 6100 by device 6114. Water not required by the system 6100 is discharged at outlet 6109. The remaining portion of the cooled expanded exhaust gas exits the cooler-condenser 6105 through conduit 6140 and is delivered to extraction valve 6106, which separates off or sequesters the CO₂ which may be delivered through outlet 6142 to a liquefaction engine as previously discussed. The remaining portion of the exhaust gas is delivered to conduit 6144 and is fluidly coupled to inlet 6112, and thus begins to be re-circulated through system 6100 again.

8. Closed-Cycle Gas Turbines with Recuperator, CO₂ Working Gas and Sequestration at High Pressure with Co-Generation of Heat and Power

Referring to FIG. 62, an illustrative closed-cycle gas turbine system 6200 with CHP and carbon dioxide sequestration by extraction at the upper pressure level of the closed-cycle system is presented. The system 6200 uses CO₂ as the working gas with recuperator and with co-generation of heat and power. The system 6200 includes a compressor turbine 6220, a low temperature heat exchanger 6221, a recuperator 6223, a combustion chamber 6224, an expansion turbine 6225, and a cooler-condenser 6226 in a closed system.

The compressor turbine 6220 aspires the working gas (CO₂) through inlet 6202 and compresses the working gas under continuous evaporation of small droplets of water provided by vaporizable liquid delivery device 6204. The droplets may be injected during intake or during the course of compression so that they are compressed along with the CO₂. Water may alternatively be supplied via external tanks as described above. The external tanks effectively replace external intercoolers. Water may also be supplied at a raised temperature and pressure as described above. The compressed working gas (CO₂) is substantially saturated with water vapor after compression and exits to conduit 6206.

The compressed working gas then enters the low temperature heat exchanger 6221 from conduit 6206 and is cooled and the water is condensed to extract a portion of the thermal energy in the mixture. The condensed water is delivered to conduit 6208, which may be delivered to device 6204. The remaining working gas is delivered by conduit 6210 to extraction valve 6222. Then a portion of the CO₂ equal to that produced in the combustion chamber 6224 is separated from the compressed and saturated working gas CO₂ and by the extraction valve 6222 and delivered to conduit 6212 for transport or storage. The remaining compressed working gas mixture then enters conduit 6214 and then the recuperator 6223 where the working gas is heated by the hot exhaust gas from the expansion turbine 6223. The heated, compressed working gas mixture leaves the recuperator 6223 via conduit 6216 and enters the combustion chamber 6224 where a hydrocarbon fuel 6218 is burned with pure oxygen 6220.

The hot exhaust gas, still a mixture of CO₂ and water, leaves the combustion chamber 6223 via conduit 6230 and enters the expansion turbine 6225 where exhaust gas is expanded. The expanded exhaust gas is supplied via conduit 6232 to the recuperator where the expanded exhaust gas heats the compressed working fluid. The cooled exhaust gas is delivered to conduit 6234 and then passed through the cooler-condenser 6226 to remove liquid. The removed liquid, or condensate, is delivered to conduit 6240 where the liquid may go to device 6204 or be discharged. The cooled and dry working gas (CO₂) is delivered by conduit 6238 to inlet 6202 and is re-circulated through the system 6200, starting with the compressor 6220.

9. Closed-Cycle Gas Turbines with Recuperator between Two Expansion Turbines

Referring now to FIG. 63, an illustrative closed-cycle gas turbine system 6310 with two-staged expansion before and after the recuperator is provided. The closed-cycle gas turbine system 6310 includes a compressor 6300, a recuperator 6301, a high temperature heat exchanger 6302 or combustion chamber, first and second expansion turbines 6303, 6304, and a cooler condenser 6305. The compressor 6300 and expansion turbines 6303, 6304 may be mounted on the same shaft 6309 and used to drive a generator 6306 to produce electricity.

The compressor turbine 6300 aspires a working gas through inlet 6312 and compresses the working gas under continuous evaporation of small droplets of vaporizable liquid (e.g., water) delivered by vaporizable liquid delivery device 6314. The droplets are injected during air intake or during the course of compression so that they are compressed along with the gas. Vaporizable liquid may also be supplied via external tanks as described above. The external tanks effectively replace external intercoolers. Vaporizable liquid may also be supplied at a raised temperature and pressure as described above. The compressed working gas is saturated with vapor after compression and is delivered by conduit 6316 to recuperator 6301.

The compressed working gas passes through the recuperator 6301 and is heated by the hot gas from the first expansion turbine 6303. Then the working gas enters a high temperature heat exchanger 6302 via conduit 6318 where the working gas is further heated. In cases operating in a semi-closed cycle where an auxiliary compressor is used, a combustion chamber or piston engine may be substituted for the high temperature heat exchanger 6302. The heated working gas is then delivered by conduit 6320 to first expansion turbine 6303 and expanded before passing via conduit 6322 through the recuperator 6301. The expansion ratio of the first expansion turbine 6303 is determined such that the temperature of the expanded working gas (mixture) after expansion is within the mechanical constraints of the recuperator 6301. In some cases, the first expansion turbine's ratio may be between approximately two and five times higher than the second expansion turbine 6304.

After the recuperator 6301, the once-expanded working gas is delivered by conduit 6324 to and expanded further by a second expansion turbine 6304 to the base or ambient pressure. The second expansion turbine 6204 expands the working gas mixture sufficiently so that the temperature of the working gas after the second expansion is near the dew point of the mixture. The fully expanded, or twice-expanded, working gas is delivered by conduit 6326 to and cooled by the cooler-condenser 6305 to condense the vaporizable liquid for re-use in the compressor. The condensed liquid is delivered to conduit 6307, which has pump 6308, and may be delivered to device 6314 for use again in system 6310. The remaining working fluid is delivered by conduit 6328 to inlet 6312 for re-use.

10. Closed Cycle Aircraft Gas Turbine Engine with a Recuperator and Compression with Vaporizable Fuel

Referring to FIG. 64, an illustrative turbo fan engine 6400 operating in a closed cycle mode with the combustion air supplied through an auxiliary compressor turbine is presented. FIG. 65 is a theoretical, schematic S-T diagram of the thermodynamic process for the engine 6400 or system shown in FIG. 64. The main power turbine may be significantly reduced in size because the base pressure of the closed-cycle main power turbine may be significantly above ambient pressure at cruising altitudes for an aircraft utilizing engine 6400. For example, given a cruising altitude with ambient pressure of approximately 250 mbar, the closed cycle main power turbine may have a base pressure of approximately 5 bar allowing the closed cycle main power turbine to be approximately 1/20^(th) the size of an open-cycle turbo fan engine.

The turbo fan engine 6400 includes a compressor turbine 6440, a recuperator 6441, a combustion chamber 6442, an expansion turbine 6443, a pump (not shown), a recirculation conduit, and a cooler-condenser 6444. The compressor turbine 6440 compresses the working gas together with injected droplets under continuous vaporization of the droplets or by injecting droplets into the area between two consecutive compressor stages. In some cases the vaporizable liquid may be fuel. Alternatively, the vaporizable liquid may be supplied via external tanks. The tanks preferably weigh no more than the weight that is saved by the reduction in fuel consumption and the reduction in component size due to this turbo fan engine 6400. Liquid may also be supplied at a raised temperature and pressure as described above. The compressed working gas enters the recuperator 6441 where the compressed gas is heated by the hot exhaust gas from the expansion turbine 6443 before the working gas enters the combustion chamber 6442.

A fan 6448, which at the intake, slightly compresses and accelerates a larger amount of air than is channelled through the auxiliary compressor turbine 6445. The auxiliary compressor turbine 6445 compresses a portion of the air from the fan 6448, and after compressing the portion air passes into the combustion chamber 6442 where the air burns with injected fuel to heat the circulating working gas in the engine 6400. After expansion in the expansion turbine 6443, part of the expanded working gas (corresponding to the air) is extracted and expanded in the auxiliary expansion turbine 6446 before the extracted working gas is accelerated in the jet-nozzle 6447 to produce thrust together with the air slightly compressed by the large fan 6448.

The majority of the working gas is, however, re-circulated in a closed cycle and passes through the recuperator 6441 to heat the compressed working gas from the compressor turbine 6440. Afterwards, the working gas is further cooled in the cooler-condenser 6444 and a corresponding amount of water condenses which is re-circulated to the compressor turbine 6440 by means of the pump. The slightly compressed air from the fan 6449 cools the working gas in the cooler-condenser 6444. Hence, its temperature is slightly increased and the corresponding thrust produced by expanding the compressed air in the jet-nozzle 6447 improves.

11. Closed Cycle System for Waste Heat Recovery

Referring to FIG. 66, an illustrative system 6600 for waste heat recovery is presented. FIG. 42 is a theoretical, schematic S-T diagram corresponding to the thermodynamic process for the system 6600 shown in FIG. 66. The closed-cycle turbine system 6600 recovers waste heat at approximately 400° C. from an internal combustion engine or the like. The system 6600 includes a compressor 6680, a heat exchanger 6681, an expansion turbine 6682, and a cooler-condenser 6683 for liquid recovery.

The compressor turbine 6680 aspires a working gas at inlet 6602 and compresses the working gas under continuous evaporation of small droplets of vaporizable liquid (e.g., water) provided by vaporizable liquid delivery device 6604. The droplets are injected during air intake or during the course of compression so that they are compressed along with the working gas. The compressed gas is saturated with vapor after compression and is delivered by conduit 6606 to the heat exchanger 6681. The compressed working gas mixture is heated in the heat exchanger 6681 using a waste heat source. Thermal energy is supplied to heat exchanger 6681 by waste heat, which is delivered to heat exchanger 6681 by inlet 6686 and is removed by outlet 6687. The working gas is delivered by conduit 6308 to the expansion turbine 6682 and expanded to the base pressure by the expansion turbine 6682. The expanded working gas passes via conduit 6610 to the cooler-condenser 6683 to be cooled, condensing the majority of the vaporizable liquid. The condensed liquid, or condensate, is delivered to conduit 6684. Conduit 6684 and pump 6685 recycle the liquid to device 6604.

12. Closed Cycle System with Piston Compressor and Expansion Turbine

Referring to FIG. 67, an illustrative closed-cycle combined piston compressor/expansion turbine system 6700 is presented. The closed-cycle piston compressor-expansion turbine system 6700 includes a screw compressor 6720 having an internal compression space of a predetermined volume, a recuperator 6721, an externally fired high temperature heat exchanger 6722 or combustor, coupled shafts 6725, a gear, a cooler-condenser 6724, and an expansion turbine 6723.

The working gas preferably has a high isentropic exponent, such as Argon (Ar). The screw compressor 6720 aspires at inlet 6702 a working gas and compresses the working gas under continuous evaporation of small droplets of vaporizable liquid (e.g., water) provided by vaporizable liquid delivery device 6704. The droplets may be injected into the internal compression space during compression so that they are compressed along with the working gas. Vaporizable liquid may also be supplied via external tanks as described above. The external tanks effectively replace external intercoolers. Vaporizable liquid may also be supplied at a raised temperature and pressure as described above. The compressed gas is substantially saturated with vapor after compression and conduit 6706 delivers the compressed working gas to the recuperator 6721.

The compressed working gas then enters the recuperator 6721 where the working gas is heated by the hot exhaust gas from the expansion turbine 6723. The heated, compressed working gas mixture leaves the recuperator 6721 via conduit 6708 and enters heating unit 6710, which may be the high temperature heat exchanger 6722 or combustor. The working gas heated in heating unit 6710 prepares an exhaust gas.

The exhaust gas leaves the heating unit 6710 via conduit 6712 and enters the expansion turbine 6723 where the exhaust gas is expanded. The expanded working gas, or expanded exhaust gas, is supplied via conduit 6714 to the recuperator 6721 where the expanded exhaust gas heats the compressed working gas from the compressor 6720. The expansion turbine 6723 drives the screw compressor 6720 through coupled shafts 6725 where a gear 6716 balances the rotation speed of the turbine 6723 with that of the screw compressor 6720. The generator 6726 is coupled to the expansion turbine to generate electricity. In some embodiments a rotary vane compressor or reciprocating piston compressor may be used instead of the screw compressor.

13. Open-Cycle Gas Turbines with Heat Exchanger between Two Compression Turbines

Referring to FIG. 68, an illustrative open-cycle gas turbine system 6800 with compression and recovery of the vaporizable liquid before the second adiabatic compression takes place is presented. FIG. 69 is a theoretical, schematic S-T diagram of the thermodynamic process for the system 6800 shown in FIG. 68. The open-cycle gas turbine system 6800 includes first and second compressors 6880, 6884, a cooler-condenser 6881, a pump 6883, a combustion chamber 6885, and an expansion turbine 6886. The compressor 6880, 6884 and expansion turbines 6886 may be mounted on the same shaft (not shown) and used to drive a generator (not shown) to produce electricity.

The first compressor turbine 6880 aspires a working gas at inlet 6802 and compresses the working gas under continuous evaporation of small droplets of vaporizable liquid (e.g., water) provided by vaporizable liquid delivery device 6804. The droplets are injected during air intake or during the course of compression so that they are compressed along with the working gas. Vaporizable liquid may also be supplied via external tanks as described above. The external tanks effectively replace external intercoolers. Vaporizable liquid may also be supplied at a raised temperature and pressure as described above. The compressed gas is substantially saturated with vapor after compression and delivered by conduit 6806 to the cooler-condenser 6881.

The compressed mixture then enters the first cooler-condenser 6881, is cooled, and the majority of the vaporizable liquid is condensed. The condensed liquid, or condensate, is delivered to conduit 6808, which has a pump 6883. The pump 6883 re-circulates the condensed liquid so that the liquid can be injected into the compressor 6880 with device 6804. Then, the working gas passes via conduit 6810 to the second compressor 6884, where the once-compressed working gas is compressed without the addition of vaporizable liquid to form a twice-compressed working gas.

The twice-compressed working gas goes on via conduit 6812 to a heating unit 6818, e.g., the combustion chamber 6885, where the twice-compressed working gas combines with fuel and combusts, producing a hot exhaust gas. In some cases, the heating unit 6818 may be a high temperature heat exchanger or piston engine. The hot exhaust gas is delivered by conduit 6814 to the expansion turbine 6886 where the heat exhaust gas is expanded to base pressure.

14. Closed-Cycle Gas Turbines with Recuperator between Two Compression Turbines

Referring to FIG. 70, an illustrative closed-cycle gas turbine system 7000 with compression before and after the recuperator is presented. The efficiency of the system 7000 may reach approximately 60% when using turbines with high efficiency. In addition the system 7000 performs well at lower compression and expansion ratios. Typically second compression ratio may be between approximately 2:1 and approximately 4:1. In cases when the temperature increase in the combustion chamber is higher, the compression and expansion ratios may be higher. Typically, total compression and expansion ratios may be between approximately 3:1 and approximately 20:1. If the temperature of the working gas after being compressed in the first compressor 7020 is too high to allow sufficient heat to be “recovered” in the recuperator, a second expansion turbine may be used as shown in FIG. 71 below. FIG. 36 is a theoretical, schematic S-T diagram of the thermodynamic process carried out by the system 7000 shown in FIG. 70.

The closed-cycle gas turbine system 7000 includes first and second compressors 7020, 7022, a recuperator 7021, a heating unit 7012 (e.g., a combustion chamber or heat exchanger 7023), a cooler-condenser 7018, and an expansion turbine 7024. The compressors and expansion turbines may be mounted on the same shaft 7026 and used to drive a generator 7027 to produce electricity. The first compressor turbine 7020 aspires through inlet 7002 a working gas and compresses the working gas with the evaporation of vaporizable liquid, which is provided by vaporizable liquid delivery device 7004. The compression process may occur under continuous evaporation of small droplets of vaporizable liquid (e.g., water) delivered by device 7004. The droplets are injected into the working gas during intake or during the course of compression so that they are compressed along with the working gas. Vaporizable liquid may also be supplied via external tanks as described above. The compressed gas is saturated with vapor after compression and is delivered by conduit 7006 to the recuperator 7021.

The compressed mixture passes through the recuperator 7021 and is heated by the hot gas from the expansion turbine 7024. After the recuperator 7021, the working gas is delivered by conduit 7008 to the second compressor 7024 and passes through the second compressor 7024, which further heats the working gas (e.g., gas-vapor mixture). After passing through the second compressors, the twice-compressed working gas passes via conduit 7010 to a heating unit 7012, which may be the combustion chamber or piston 7023 where fuel and oxygen are supplied, and the twice-compressed working gas and fuel burn to produce a hot exhaust gas. The heating unit 7012 is preferably a combustion chamber 7023. Alternatively, the heating unit 7012 might be a high temperature heat exchanger. In cases operating in a semi-closed cycle, an auxiliary compressor may supply the oxygen or air for combustion.

The heated exhaust gas is delivered by conduit 7014 to expansion turbine 7024 and expanded in the expansion turbine 7024 before passing via conduit 7016 through the recuperator 7021 to transfer thermal energy to the newly compressed working gas from the first compressor turbine 7020. After the recuperator 7021, the exhaust gas passes via conduit 7025 to a cooler-condenser 7018, which removes the liquid, or condensate. The condensate is delivered to conduit 7030 and be fluidly coupled to device 7004 to recycle the liquid or may discharge. The remaining working fluid exists the cooler-condenser 7018 through conduit 7032 and is received by inlet 7002 of the first compressor turbine 7020.

15. Closed-Cycle Gas Turbines with Recuperator between Two Compression Turbines and between Two Expansion Turbines

Referring to FIG. 71 an illustrative closed-cycle gas turbine system 7100 with compression before and after the recuperator and two-staged expansion before and after the recuperator is presented. The closed-cycle gas turbine system 7100 includes first and second compressors 7140, 7142, a recuperator 7141, a combustion chamber 7143, a cooler-condenser, and first and second expansion turbines 7144, 7145. The compressor and expansion turbines may be mounted on the same shaft 7147 and used to drive a generator 7148 to produce electricity.

The first compressor turbine 7140 aspires a working gas at inlet 7102 and compresses the working gas under continuous evaporation of small droplets of vaporizable liquid (e.g., water) provided by vaporizable liquid delivery device 7104. The droplets may be injected during working gas intake or during the course of compression so that they are compressed along with the gas. Vaporizable liquid may also be supplied at a raised temperature and pressure as described above. The compressed gas is substantially saturated with vapor after compression and is delivered by conduit 7106 to the recuperator 7141. The compressed working gas mixture passes through the recuperator 7141 and is heated by the hot gas from the first expansion turbine 7144. Then, the mixture passes via conduit 7108 through the second compressor 7142 to produce a twice-compressed working gas.

The twice-compressed working gas is delivered by conduit 7110 to a heating unit 7112, e.g., combustion chamber 7143, where twice-compressed working gas is heated to form a hot exhaust gas. Thus for example, if the heating unit 7112 is a combustion chamber 7143, the twice-compressed working gas combines with fuel and combusts, producing the hot exhaust gas. The heating unit 7112 may also be a piston engine. The heating unit 7112 might also be a high temperature heat exchanger. The exhaust gas enters, via conduit 7114, the first expansion turbine 7144 where the exhaust gas is expanded to produce an expanded exhaust gas to produce energy.

The expanded exhaust gas is delivered by conduit 7116 to the recuperator 7141 to help heat the compressed working gas passing there through. After the recuperator 7141, the working gas is delivered by conduit 7118 to the second expansion turbine 7145 and further expanded to the base pressure. The twice-expanded exhaust gas leaves the second expansion turbine 7145 by conduit 7120 and is delivered to a cooler-condenser 7122 where the twice-expanded exhaust gas is cooled. A condensate may be removed from the exhaust gas by the cooler-condenser 7122. The remaining exhaust gas is delivered by conduit 7124 to inlet 7102 of first compressor 7140.

16. Closed-Cycle Gas Turbine System for Cooling

Referring to FIG. 72 an illustrative closed-cycle gas turbine system 7212 for cooling is presented. FIG. 73 is a theoretical, schematic S-T diagram of the thermodynamic process in the system 7212 of FIG. 72. The closed-cycle gas turbine system 7212 for cooling includes a compressor 7200, a recuperator 7201, a heat exchanger 7202, first and second expansion turbines 7203, 7206, a cooler-condenser 7204, and a low temperature heat exchanger 7207. The compressor and expansion turbines may be mounted on the same shaft 7210 and produce additional electricity with a generator (not shown) if surplus mechanical power is available.

The compressor turbine 7200 aspires working gas at an inlet 7214, such as helium, at the base pressure of the system 7212. The base pressure may be at, below, or above ambient pressure. For example in low load conditions, the base pressure may be below atmospheric pressure to reduce power production. The compressor turbine 7200 compresses the working gas under continuous vaporization of vaporizable liquid provided by vaporizable liquid delivery device 7216. The working gas may, for example, be compressed under continuous evaporation of small droplets of vaporizable liquid from device 7216. The droplets may be injected into the working gas during intake or during the course of compression so that they are compressed along with the working gas. Vaporizable liquid may also be supplied via external tanks as described above. The external tanks effectively replace external intercoolers. Vaporizable liquid may also be supplied at a raised temperature and pressure as described above. The compressed gas is substantially saturated with vapor after compression and is delivered by conduit 7218 to the recuperator 7201.

The compressed working gas enters the recuperator 7201 where the compressed working gas is heated by the hot exhaust gas from the first expansion turbine 7203. After leaving the recuperator 7201 the heated working gas mixture enters, via conduit 7220, the heat exchanger 7202 to further increase the working gas temperature. The heat exchanger 7202 may, in turn, be heated by burning fuel or by any other source of heat as, for example, waste heat from a gas turbine or extracted steam from a steam turbine.

The heated working gas mixture is delivered by conduit 7222 to the first expansion turbine 7203. The compressed working gas expands in the first expansion turbine 7203 (state change D→E in FIG. 73) to an intermediate pressure above the base pressure of the system 7212 and is passed via conduit 7224 to the recuperator 7201 to transfer heat to the compressed working gas from the compressor turbine 7200. In the cooler-condenser 7204, the working gas is cooled down to ambient temperature and the vaporised liquid condenses (state change F→G in FIG. 73). The condensed liquid, or condensate, is delivered to conduit 7205 from where it may be delivered to device 7216. The remaining once-expanded exhaust gas is delivered by conduit 7230 to the second expansion turbine 7206. In the second expansion turbine 7206, the once-expanded working gas, or exhaust gas, is expanded again to the base pressure of the system and forms a twice-expanded exhaust gas, or working gas, or cold working gas.

Because the working gas temperature at the beginning of the second expansion is ambient temperature, the second expansion decreases the working gas temperature far below ambient temperature. Thus, temperature is low enough to liquefy natural gas (or other gases with a similar critical temperature, such as carbon dioxide, air, oxygen, nitrogen, or the like) can be achieved. The cold working gas is delivered by conduit 7232 to the low temperature heat exchanger 7207 where the cold working gas cools pressurized natural gas down to the temperature where working gas saturation pressure reaches ambient pressure. In the system 7212 of FIG. 72, the pressurised natural gas supplied through the inlet 7208 leaves the low temperature heat exchanger/liquefier 7207 through outlet 7209 at a temperature of around −160° C., i.e., at a vapor pressure of around 1 bar to be handled further. As it cools the pressurized natural gas, the working gas is heated (state change H→A in FIG. 73). The working gas then leaves the exchanger/liquefier 7207 through conduit 7236 and is aspired again by the compressor turbine 7200 at inlet 7214 to close the cycle.

The power producing part of the thermodynamic process of system 7212 encompasses the area delimited by the state points B, C, D, E, F in FIG. 73 and is more or less equal to the power consuming part of the thermodynamic process. The power consuming part of the thermodynamic process includes the area delimited by the state points F, G, H, A. The difference is net power produced or consumed. In case of real engines with mechanical efficiencies below 100%, the difference is transformed into heat which is removed by cooling and condensing in the heat exchanger 7204. The power producing part is run-through clockwise while the power consuming part is run-through counter clockwise as shown in FIG. 73. By adjusting the base pressure of the system 7212 the cooling power can be changed, and by adapting the compression and expansion ratios in the turbines 7200, 7203 and 7206 the desired temperature ranges for mechanical power production and cooling power can be achieved.

C. Mixed Open/Closed-Cycle Gas Turbines

1. Mixed Open/Closed-Cycle Gas Turbines with Recuperator and Internal Combustion Chamber

Referring now to FIG. 74 an illustrative gas turbine system 7400 with a closed-cycle working gas cycle and an open-cycle supply of air to burn fuel in an internal combustion chamber is presented. The system 7400 may include first and second compressor turbines 7460, 7462, an auxiliary compressor turbine 7467, a mixer 7469, a recuperator 7461, a combustion chamber 7463, first and second expansion turbines 7464, 7465, an auxiliary expansion turbine 7471, a pump 7476, a recirculation conduit 7475, a cooler-condenser 7466, and a generator 7474.

The first compressor turbine 7460 aspires a working gas at inlet 7402 and compresses the working gas together with injected droplets under continuous vaporization of the droplets or by injecting droplets into the area between two consecutive compressor stages. The liquid or liquid droplets are provided by a vaporizable liquid delivery device 7404. The vaporizable liquid delivery device might also include external tanks in which case the vaporizable liquid may be supplied via the external tanks as described above. The external tanks effectively replace external intercoolers. Vaporizable liquid may also be supplied at a raised temperature and pressure as described above. The compressed working gas is preferably fully saturated before leaving the first compressor 7460 through conduit 7406. The compressed working gas then enters the recuperator 7461 where the compressed working gas is heated by the remaining portion of exhaust gas from the first expansion turbine 7464. The compressed working gas is delivered by conduit 7408 to the mixer 7469. The mixer 7469 also receives compressed air from conduit 7410.

The auxiliary compression turbine 7467 aspires ambient air and compresses the air and delivers the compressed air to the conduit 7410. The compressed air and the compressed working gas are mixed in the mixer 7469 before they are delivered by conduit 7412 to the second compression turbine 7465. After the second compression, the mixed working gas is delivered by conduit 7414 to combustion chamber 7463. In the combustion chamber 7463, the mixed working gas is burned with a fuel to produce an exhaust gas.

The exhaust gas is then delivered by conduit 7416 to the first expansion turbine 7464 where the exhaust gas is expanded to produce an expanded exhaust gas and energy. A portion of the exhaust gas is extracted from one of the stages of the first expansion turbine 7464 in an amount equivalent to the mass of the fresh air delivered by conduit 7410 to the auxiliary compressor turbine 7467. The extracted portion of exhaust gas is delivered by conduit 7470 to the auxiliary expansion turbine 7471. The auxiliary expansion turbine 7471 expands the extracted exhaust gas down to ambient pressure and discharges that portion of the exhaust gas into the environment through exhaust outlet 7472.

The remaining portion of the exhaust gas is delivered by conduit 7420 to the recuperator 7461. The exhaust gas passes through the recuperator 7461 and is delivered by conduit 7422 to the second expansion turbine 7465. In the second expansion turbine 7465, the exhaust gas is expanded to base pressure and thus produces energy and a twice-expanded exhaust gas. The twice-expanded exhaust gas is delivered by conduit 7424 to the cooler-condenser 7466. In the cooler-condenser 7466, the twice-expanded exhaust gas is further cooled and the water vaporized in the course of the compression in the first compressor turbine condenses. The condensed water, or condensate, is delivered to conduit 7475 and with the help of pump 7476 is recycled to the vaporizable liquid delivery device 7404 on the first compressor 7460. The dried remaining portion, or dried exhaust gas, which is at base pressure, is again aspired by the first compressor turbine 7460 through inlet 7424 to close the cycle. All the turbines (compression 7467, 7460, 7462 and expansion 7464, 7465, 7471) may be mounted on the same shaft 7473 and drive a generator 7474 to generate electricity.

2. Mixed Open/Closed-Cycle Gas Turbines with Piston Compressor and Auxiliary Compressor and Auxiliary Expansion Turbine

Referring to FIG. 75, an illustrative combined piston compressor/expansion turbine system 7500 for carrying out a semi-closed cycle is presented. The combined piston compressor/expansion turbine system 7500, or arrangement, for carrying out a semi-closed cycle may include an auxiliary compressor 7540, an auxiliary expansion turbine 7545, a screw compressor 7541, recuperator 7542, an expansion turbine 7544, a combustion chamber 7543, and a cooler-condenser 7546.

The auxiliary screw compressor 7540 compresses fresh air aspired through inlet 7502. The auxiliary screw compressor 7540 compresses the air under vaporization of water to the base pressure provided by a first vaporizable liquid delivery device 7504. The compressed air/steam mixture is delivered by conduit 7506 to the main screw compressor 7541 and mixes with the feed gas to form a working gas. The working gas (or feed gas and air-steam mixture) is aspired by the main screw compressor 7541 through inlet 7508. The main screw compressor 7541 compresses the working gas to produce a compressed working gas.

The compressed working gas is delivered by conduit 7510 to and passes through the recuperator 7542 where the compressed working gas is heated by the exhaust gas from the main expansion turbine 7544. The pre-heated compressed working gas leaves the recuperator through conduit 7512 and enters the combustion chamber 7543 where the compressed working gas and fuel are burned. Afterwards, the effluent of hot working gas, or exhaust gas, is delivered by conduit 7514 to the expansion turbine 7544. In the expansion turbine 7544, the exhaust gas is expanded down to the base pressure.

After the main expansion turbine 7544, the expanded working gas is delivered to outlet 7516, which is a divider fluidly coupled to first conduit 7518 and a second conduit 7520. A smaller portion of the expanded exhaust gas is delivered into the first conduit 7518 and passed to an auxiliary expansion turbine 7525. The portion of the exhaust gas delivered to conduit 7518 preferably corresponds to the aspired air that was compressed by the auxiliary screw compressor 7540 and the burned fuel. The portion of the exhaust gas delivered into first conduit 7518 is further expanded in the auxiliary expansion turbine 7545 down to ambient pressure and released to the environment through outlet 7522. The remaining part of the exhaust gas is delivered into second conduit 7520 and passed through the recuperator 7542 to heat the compressed working gas from the main screw compressor 7541. The remaining exhaust gas is then delivered by conduit 7524 to the cooler-condenser 7546 for further cooling and removal of condensation of the water vaporized in the course of compression. The condensed water, or condensate, is delivered to conduit 7526 and conduit 7528. Conduit 7526 delivers water to first the first vaporizable liquid delivery device 7504 at compressor 7540. Conduit 7528 delivers water to the second vaporizable liquid delivery device 7530 at main screw compressor 7541.

Thus, the condensed water may be re-circulated to the auxiliary and main screw compressors 7540, 7541 for repeated vaporization. Of course, that part of the working gas which is separated to be expanded in the auxiliary expansion turbine 7545 may also pass through the recuperator 7542 to be cooled to a temperature between the exhaust temperature of the main expansion turbine 7544 and the compressed end temperature after the main screw compressor 7541.

The main screw compressor 7541 and the main expansion turbine 7544 are connected through shafts 7532, 7534, and gear 7547. The auxiliary screw compressor 7540 and the auxiliary expansion turbine 7545 are connected through shafts 7536, 7538, and gear 7548. Of course, all compressors and turbines may be mounted on common shafts or be connected through a single gear. The main expansion turbine 7544 drives a generator 7549 to produce electricity in the described embodiment.

III. Additional Aspects and Comments

Additional aspects, systems, and methods will now be presented.

Referring to FIG. 16, an open-cycle gas turbine system for producing power and optionally heat includes: a compressor for receiving a working gas and compressing the working gas to produce a compressed working gas; a vaporizable liquid delivery device associated with the compressor for delivering a vaporizable liquid to the working gas; a heat exchanger fluidly coupled to the compressor for receiving the compressed working gas and cooling the compressed working gas to produce a cooled, compressed working gas; a recuperator for receiving the cooled, compressed working gas from the heat exchanger and adding thermal energy to produce a heated, compressed working gas; a combustion chamber fluidly coupled to the recuperator for receiving the heated, compressed working gas from the recuperator and combusting the heated, compressed working gas to produce an exhaust gas; an expansion turbine fluidly coupled to the combustion chamber for receiving the exhaust gas and expanding the exhaust gas to develop power and to produce an expanded exhaust gas; and wherein the recuperator is fluidly coupled to the expansion turbine for receiving the expanded exhaust gas.

Referring to FIG. 16, an open-cycle gas turbine system for producing power and optionally heat, the system includes: a compressor for receiving a working gas and compressing the working gas to produce a compressed working gas; a vaporizable liquid delivery device associated with the compressor for delivering a vaporizable liquid to the working gas; a heat exchanger fluidly coupled to the compressor for receiving the compressed working gas and cooling the compressed working gas to produce a cooled, compressed working gas; a recuperator for receiving the cooled, compressed working gas from the heat exchanger and adding thermal energy to produce a heated, compressed working gas; a combustion chamber fluidly coupled to the recuperator for receiving the heated, compressed working gas from the recuperator and combusting the heated, compressed working gas to produce an exhaust gas; an expansion turbine fluidly coupled to the combustion chamber for receiving the exhaust gas and expanding the exhaust gas to develop power and to produce an expanded exhaust gas; and wherein the recuperator is fluidly coupled to the expansion turbine for receiving the expanded exhaust gas.

Referring to FIG. 16, a method of producing power with an open-cycle gas turbine, the method includes the steps of: compressing a working gas to produce a compressed working gas; wherein the step of compressing a working gas comprises delivering a vaporizable liquid to the working gas; cooling the compressed working gas in a heat exchanger to produce a cooled, compressed working gas; adding thermal energy in a recuperator to the cooled, compressed working gas to produce a heated, compressed working gas; combusting the heated, compressed working gas in a combustion chamber o produce an exhaust gas; expanding the exhaust gas in an expansion turbine to develop power and to produce an expanded exhaust gas; and supplying thermal energy to the recuperator from the expanded exhaust gas.

Referring to FIG. 20, an open-cycle gas turbine system, the system includes: a compressor for receiving a working gas and compressing the working gas to produce a compressed working gas; a vaporizable liquid delivery device associated with the compressor for delivering liquid droplets to the working gas; a recuperator fluidly coupled to the compressor for receiving the compressed working gas from the compressor and delivering thermal energy to the compressed working gas to produce a heated, compressed working gas; a combustion chamber fluidly coupled to the recuperator for combusting the heated, compressed working gas to produce an exhaust gas; an expansion turbine fluidly coupled to the combustion chamber for receiving the exhaust gas and removing energy from the heat exhaust gas to produce an expanded exhaust gas; a heat exchanger fluidly coupled to the expansion turbine for receiving the expanded exhaust gas and removing thermal energy from the expanded exhaust gas to produce a cooled, expanded exhaust gas; and a conduit associated with the heat exchanger for receiving the cooled, expanded exhaust gas and delivering the cooled, expanded exhaust to the recuperator.

Referring to FIG. 33, an open-cycle gas turbine system, the system includes: a first compressor having a vaporizable liquid delivery device, the first compressor for receiving a working gas and compressing the working gas to form a compressed working gas; a recuperator fluidly coupled to the compressor, the recuperator for receiving the compressed working gas and providing thermal energy to the compressed working gas to produce a heated, compressed working gas; a first expansion turbine fluidly coupled to the recuperator for receiving the heated, compressed working gas and operable to expand the heated, compressed working gas to produce energy and a once-expanded working gas; a conduit for delivering the once-expanded working gas from the first expansion turbine to the recuperator; and a second expansion turbine fluidly coupled to the recuperator for receiving the once-expanded working gas and operable to expand the once-expanded working gas to produce energy and to produce a twice-expanded working gas.

Referring to FIG. 35, an open-cycle gas turbine system, the system includes: a compressor having a vaporizable liquid delivery device, and wherein the compressor is operable to receive a working gas and compress the working gas to produce a compressed working gas; a recuperator fluidly coupled to the compressor for receiving the working gas and adding thermal energy to produce a once-heated, compressed working gas; a second compressor fluidly coupled to the recuperator for receiving the once-heated, compressed working gas and further compressing the once-heated, compressed working gas to produce a twice-compressed working gas; a combustion chamber fluidly coupled to the second compressor for receiving the twice-compressed working gas and combusting the twice-compressed working gas to produce an exhaust gas; a expansion turbine fluidly coupled to the combustion chamber for receiving the exhaust gas and expanding the exhaust gas to produce an expanded exhaust gas; and a conduit fluidly coupled between the recuperator and the expansion turbine for delivering the expanded working gas from the expansion turbine to the recuperator wherein the expanded working gas provides thermal energy.

Referring to FIG. 37, an open-cycle gas turbine system, the system includes: a first compressor for receiving a working gas, the first compressor having a vaporizable liquid delivery device and operable to produce a compressed working gas; a cooler-condenser fluidly coupled to the first compressor for receiving the compressed working gas and cooling the compressed working gas to produce a condensed liquid and a cooled, compressed working gas; a conduit for delivering the condensed liquid from the cooler-condenser to the vaporizable liquid delivery device; a second compressor fluidly coupled to the cooler-condenser for receiving the cooled compressed working gas and operable to produce a twice-compressed working gas; a combustion chamber fluidly coupled to the second compressor for receiving the twice-compressed working gas and combusting the twice-compressed working gas to produce an exhaust gas; and an expansion turbine fluidly coupled to the combustion chamber for receiving the exhaust gas and operable to expand the exhaust gas to develop energy and produce an expanded exhaust gas.

Referring to FIG. 39, an open-cycle gas turbine system, the system includes: a first compressor having a vaporizable liquid delivery device and operable to receive a working gas and to compress the working gas to produce a compressed working gas; a recuperator fluidly coupled to the first compressor for receiving the compressed working gas and operable to provide thermal energy to the working gas to produce heated, compressed working gas; a second compressor fluidly coupled to the recuperator for receiving the heated, compressed working gas from the recuperator and compressing the heated, compressed working gas to produce a twice-compressed working gas; a combustion chamber fluidly coupled to the second compressor for receiving the twice-compressed working gas and combusting the twice-compressed working gas to produce an exhaust gas; a first expansion turbine fluidly coupled to the combustion chamber for receiving the exhaust gas and operable to produce a once-expanded exhaust gas; a conduit fluidly coupled to the recuperator and the first expansion turbine, the conduit for delivering the once-expanded exhaust gas from the first expansion turbine to the recuperator; wherein the recuperator is further operable to receive thermal energy from the once-expanded exhaust gas and to produce a cooled, once-expanded exhaust gas; and a second expansion turbine fluidly coupled to the recuperator for receiving the cooled, once-expanded exhaust gas and expanding the cooled, once-expanded exhaust gas to produced a twice-expanded exhaust gas and energy.

Referring to FIG. 48, an open-cycle gas turbine system for cooling, the system includes: a compressor having a vaporizable liquid delivery device, the compressor operable to receive a working gas and produce a compressed working gas; a recuperator fluidly coupled to the compressor for receiving the compressed working gas and providing thermal energy to the compressed working gas to produce heated, compressed working gas; a combustion chamber fluidly coupled to the recuperator for receiving the heated, compressed working gas and combusting the heated, compressed working gas to produce an exhaust gas; a first expansion turbine fluidly coupled to the combustion chamber for receiving the exhaust gas and expanding the exhaust gas to produce an expanded exhaust gas and energy; wherein the recuperator is fluidly coupled to the first expansion turbine for receiving the expanded exhaust gas from the first expansion turbine and removing thermal energy to produce a cooled, expanded exhaust gas; a cooler-condenser fluidly coupled to the recuperator for receiving the cooled, expanded exhaust gas and producing a dried working gas; a second expansion turbine fluidly coupled to the cooler-condenser for receiving the dried working gas and producing a cold working gas; and a low temperature heat exchanger fluidly coupled to the second expansion turbine for receiving the cold working gas and delivering thermal energy to the cold working gas.

Referring to FIG. 68, n open-cycle gas turbine system, the system includes: a first compressor for receiving a working gas, the first compressor having a vaporizable liquid delivery device and operable to produce a compressed working gas; a cooler-condenser fluidly coupled to the first compressor for receiving the compressed working gas and cooling the compressed working gas to produce a condensed liquid and a cooled, compressed working gas; a conduit for delivering the condensed liquid from the cooler-condenser to the vaporizable liquid delivery device; a second compressor fluidly coupled to the cooler-condenser for receiving the cooled compressed working gas and operable to produce a twice-compressed working gas; a heating unit fluidly coupled to the second compressor for receiving the twice-compressed working gas and providing thermal energy to the twice-compressed working gas to produce an exhaust gas; and an expansion turbine fluidly coupled to the heating unit for receiving the exhaust gas and operable to expand the exhaust gas to develop energy and produce an expanded exhaust gas.

Referring to FIG. 1-3, A turbo compressor for receiving a working gas and producing a compressed working gas, the compressor includes: a plurality of stators; a plurality of impellers; a housing surrounding the plurality of stators and plurality of impellers and having an inlet and an outlet; a vaporizable liquid delivery device for providing a vaporizable liquid to the working gas; and wherein the vaporizable liquid delivery device is sized and configured to saturate the working gas and vaporize all the liquid provided to the vaporizable liquid delivery device.

A method for compressing a working gas in an turbo compressor having a plurality of stages, the method includes: introducing the working gas through an inlet into a housing of the turbo compressor; providing vaporizable liquid between at least one stage of the plurality of stages of the turbo compressor; discharging the working gas through an outlet; and wherein the step of providing a vaporizable liquid comprises the step of providing the vaporizable liquid at a rate, size, and location such all the liquid is vaporized before the working gas is discharged.

Referring to FIGS. 8-9, a semi-closed turbine system for generating power, the system includes: a first compressor for receiving a fresh working gas and compressing the fresh working gas to produce a first compressed working gas; a second compressor having a vaporizable liquid delivery device, the second compressor for receiving a recycled working gas and producing a compressed, recycled working gas; a recuperator fluidly coupled to the second compressor for receiving the compressed, recycled working gas and adding thermal energy to produce a heated, compressed, recycled working gas; a combustion chamber coupled to the first compressor for receiving the first compressed working gas and fluidly coupled to the recuperator for receiving the heated, compressed, recycled working gas, and operable to combust the first compressed working gas and the heated, compressed, recycled working gas to produce an exhaust gas; a first expansion turbine fluidly coupled to the combustion chamber for receiving the exhaust gas and expanding the exhaust gas to produce an expanded exhaust gas; wherein the recuperator is fluidly coupled to the expansion turbine for receiving the expanded exhaust gas and wherein the recuperator is operable to produce a cooled, expanded exhaust gas; a first conduit fluidly coupled to the recuperator for receiving the cooled, expanded exhaust gas; a second expansion turbine fluidly coupled to the first conduit and operable to receive at least a portion of the cooled, expanded exhaust gas and to expand the cooled exhaust gas to produce energy; and wherein the second compressor is fluidly coupled to the first conduit to receive at least a portion of the cooled, expanded exhaust gas and wherein the cooled, expanded exhaust gas is provided to the second compressor as the recycled working gas.

Referring to FIG. 9, the turbine system for generating power just described further includes an initial compressor fluidly coupled to the first compressor, the initial compressor for receiving a fresh feedstock and compressing the fresh feedstock to form the fresh working gas.

Referring to FIGS. 8-9, a semi-closed turbine system for generating power, the system includes: a first compressor for receiving a fresh working gas and compressing the fresh working gas to produce a first compressed working gas; a second compressor having a vaporizable liquid delivery device, the second compressor for receiving a recycled working gas and producing a compressed, recycled working gas; a combustion chamber coupled to the first compressor for receiving the first compressed working gas and fluidly coupled to the second compressor for receiving the compressed, recycled working gas, and operable to combust the first compressed working gas and the compressed, recycled working gas to produce an exhaust gas; a first expansion turbine fluidly coupled to the combustion chamber for receiving the exhaust gas and expanding the exhaust gas to produce an expanded exhaust gas; a first conduit fluidly coupled to the first expansion turbine for receiving the expanded exhaust gas; a second expansion turbine fluidly coupled to the first conduit and operable to receive at least a portion of the expanded exhaust gas and to expand the exhaust gas to produce energy; and wherein the second compressor is fluidly coupled to the first conduit to receive at least a portion of the expanded exhaust gas and wherein the expanded exhaust gas is provided to the second compressor as the recycled working gas.

Referring to FIG. 10, a semi-closed turbine system for generating power, the system includes: a first compressor having a first vaporizable liquid delivery device, the first compressor for receiving a fresh working gas and compressing the fresh working gas to produce a first compressed working gas; a second compressor having a second vaporizable liquid delivery device, the second compressor for receiving a recycled working gas and the first compressed working gas and producing a second compressed working gas; a recuperator fluidly coupled to the second compressor for receiving the second compressed working gas and providing additional thermal energy to the second compressed working gas to produce a heated, compressed working gas; a combustion chamber coupled to the recuperator for receiving the heated, compressed working gas and operable to combust the heated, compressed working gas to produce an exhaust gas; a first expansion turbine fluidly coupled to the combustion chamber for receiving the exhaust gas and expanding the exhaust gas to produce power and an expanded exhaust gas; a second expansion turbine; a first conduit fluidly coupled to the first expansion turbine and coupled to the recuperator for providing at least a portion of the expanded exhaust gas to the recuperator and fluidly coupled to the second expansion turbine for providing at least a portion of the expanded exhaust gas to the second expansion turbine; wherein the recuperator is operable to receive the expanded exhaust gas and remove thermal energy to produce a cooled exhaust gas; and a second conduit fluidly coupled the recuperator and fluidly coupled to the second compressor, the second conduit operable to deliver the cooled exhaust gas from the recuperator to the second compressor as recycled working gas.

Referring to FIG. 74, a semi-closed turbine system for producing power, the system includes: a first compressor for receiving a fresh working gas and compressing the fresh working gas to form a first compressed working gas; a second compressor for receiving a recycled working gas and compressing the recycled working gas to form a second compressed working gas; a recuperator fluidly coupled to the second compressor and operable to add thermal energy to the second compressed working gas to form a heated second working gas; a mixer fluidly coupled to the recuperator and to the first compressor for receiving the first compressed working gas and the heated second compressed working gas to form a third working gas; a third compressor coupled to the mixer for receiving the third working gas and compressing the third working gas to form a third compressed working gas; a combustion chamber fluidly coupled to the third compressor for receiving and burning the third compressed working gas to produce an exhaust gas; a first expansion turbine fluidly coupled to the combustion chamber, the first expansion turbine for receiving and expanding the exhaust gas to produce power and an expanded exhaust gas; a first conduit fluidly coupled to the first expansion turbine and fluidly coupled to the recuperator for delivery at least a portion of the expanded exhaust gas to the recuperator; a second expansion turbine; a second conduit fluidly coupled to the first expansion turbine and the second expansion turbine, the second conduit operable to deliver at least a portion of the expanded exhaust to the second expansion turbine, wherein the second expansion turbine is operable to produce power and a twice-expanded exhaust gas; a third expansion turbine; a third conduit fluidly coupled to the recuperator and to the third expansion turbine, wherein the third expansion turbine is operable to receive and expand the expanded exhaust to produce a second expanded exhaust gas; a cooler-condenser fluidly coupled to the third expansion turbine for received the second-expanded exhaust gas and removing a vaporized liquid to produce a dried working gas; and a fourth conduit fluidly coupled to the condenser-cooler and second compressor, the fourth conduit operable to deliver the dried working gas to the second compressor as the recycled working gas.

Referring to FIG. 52, a closed turbine system for producing power, the system includes: a compressor for receiving a recycled working gas and compressing the recycled working gas to produce a compressed working gas, wherein the compressor comprises a vaporizable liquid delivery device; a recuperator fluidly coupled to the compressor for receiving the compressed working gas and adding thermal energy to the compressed working gas to form a heated, compressed working gas; a high temperature heat exchanger fluidly coupled to the recuperator for receiving the heated, compressed working gas and adding thermal energy to the heated, compressed working gas to form a hot working gas; an expansion turbine fluidly coupled to the high temperature heat exchanger for receiving the hot working gas and expanding the hot working gas to form an expanded working gas and power; a first conduit fluidly coupled to the expansion turbine and fluidly coupled to the recuperator for delivering the expanded working gas to the recuperator to provide thermal energy to the recuperator; a cooler-condenser; and a second conduit fluidly coupled to the recuperator and to the cooler-condenser, wherein the cooler-condenser is operable to remove a condensable liquid from the expanded working gas and to produce the recycled working gas.

Referring to FIG. 63, a closed turbine system, the system includes: a first compressor having a vaporizable liquid delivery device, the first compressor for receiving a recycled working gas and compressing the recycled working gas to form a first compressed working gas; a recuperator fluidly coupled to the first compressor for receiving the first compressed working gas and providing additional thermal energy to form a heated, compressed working gas; a high temperature heat exchanger fluidly coupled to the recuperator for receiving the heated, compressed working gas and providing additional thermal energy to form a hot, compressed working gas; a first expansion turbine fluidly coupled to the high temperature heat exchanger for receiving the hot, compressed working gas and expanding the hot, compressed working gas to form a first expanded working gas; wherein the recuperator is fluidly coupled to the first expansion turbine to receive the first expanded exhaust gas and produce a cooled expanded exhaust gas; a second expansion turbine fluidly coupled to the recuperator for receiving the cooled expanded exhaust gas and expanding the cooled expanded exhaust gas to produce power and to produce a second expanded exhaust gas; and a cooler condenser fluidly coupled to the second expansion turbine and operable to receive the second expanded exhaust gas and to condense out a condensable liquid to produce a dried working gas, which is the working gas delivered to the first compressor.

Referring to FIG. 70, a closed turbine system, the system includes: a first compressor having a vaporizable liquid delivery device, the first compressor for receiving a working gas and compressing the working gas to form a first compressed working gas; a recuperator fluidly coupled to the first compressor for receiving the first compressed working gas and providing additional thermal energy to form a heated, compressed working gas; a second compressor fluidly coupled to the recuperator for receiving the heated compressed working gas and compressing the heated compressed working gas to form a second compressed working gas; a heating unit fluidly coupled to the recuperator for receiving the second compressed working gas and providing additional thermal energy to form a hot, compressed working gas; a first expansion turbine fluidly coupled to the heating unit for receiving the hot, compressed working gas and expanding the hot, compressed working gas to form a first expanded exhaust gas; wherein the recuperator is fluidly coupled to the first expansion turbine to receive the first expanded exhaust gas and produce a cooled expanded exhaust gas; and a cooler condenser fluidly coupled to the recuperator and operable to receive the cooled expanded exhaust gas and to condense out a condensable liquid to produce a dried working gas, which is the working gas delivered to the first compressor.

Referring to FIG. 71, a closed turbine system, the system includes: a first compressor having a vaporizable liquid delivery device, the first compressor for receiving a recycled working gas and compressing the recycled working gas to form a first compressed working gas; a recuperator fluidly coupled to the first compressor for receiving the first compressed working gas and providing additional thermal energy to form a heated, compressed working gas; a second compressor fluidly coupled to the recuperator for receiving the heated, compressed working gas and compressing the heated, compressed working gas to form a second compressed working gas; a combustion chamber fluidly coupled to the second compressor for receiving the second compressed working gas and combusting the second compressed working gas to produce an exhaust gas; a first expansion turbine fluidly coupled to the combustion chamber for receiving the exhaust gas and expanding the exhaust gas to form a first expanded exhaust gas; wherein the recuperator is fluidly coupled to the first expansion turbine to receive the first expanded exhaust gas and produce a cooled expanded exhaust gas; a second expansion turbine fluidly coupled to the recuperator for receiving the cooled expanded exhaust gas and expanding the cooled expanded exhaust gas to produce power and to produce a second expanded exhaust gas; and a cooler condenser fluidly coupled to the second expansion turbine and operable to receive the second expanded exhaust gas and to condense out a condensable liquid to produce a dried working gas, which is the working gas delivered to the first compressor.

Referring to FIG. 12, a system for producing a compressed fluid, the system includes: a compressor having a vaporizable liquid delivery device, the compressor operable to receive a working gas and to produce a compressed working gas; a recuperator fluidly coupled to the compressor for receiving the compressed working gas and operable to add thermal energy to the compressed working gas to produce a heated, compressed working gas; a heating unit fluidly coupled to the recuperator for receiving the heated, compressed working gas and operable to provide additional thermal energy to the heated, compressed working gas to produce an exhaust gas; an expansion turbine fluidly coupled to the heating unit for receiving the exhaust gas and expanding the exhaust gas to create an expanded exhaust gas and power; a first conduit fluidly coupled to the expansion turbine and the recuperator, the first conduit operable to deliver the expanded exhaust gas to the recuperator, wherein the recuperator is operable to receive the expanded exhaust gas and produce a cooled expanded exhaust gas; a cooler-condenser fluidly coupled to the recuperator for receiving the cooled, expanded exhaust gas and condensing out a condensable liquid to produce a dry exhaust gas; and a pressure tank fluidly coupled to the cooler-condenser for receiving the dried exhaust gas.

Referring to FIG. 18, an open-cycle gas turbine system, the system includes: a compressor for receiving a working gas and compressing the working gas to form a compressed working gas; the compressor further includes a plurality of stages and a plurality of channels associated with the stages; an intercooler for cooling an intermediate compressed working gas; wherein each channel of the plurality of channels is operable to remove the intermediate compressed working gas and deliver the intermediate working gas to the intercooler for the removal of thermal energy and return intermediate working gas upstream of a downstream stage; a recuperator fluidly coupled to the compressor for receiving the compressed working gas and providing thermal energy to the working gas to produce a heated working gas; a combustion chamber fluidly coupled to the recuperator for receiving the heated working gas and producing an exhaust gas; an expansion turbine fluidly coupled to the combustion chamber for receiving the exhaust gas and expanding it to produce an expanded exhaust gas and power; and a conduit fluidly coupled to the recuperator and to the expansion turbine, the conduit operable to deliver the expanded exhaust gas to the recuperator.

Referring to FIG. 22, a turbo-fan engine includes: a fan for receiving a working gas and compressing the working gas to form a first compressed working gas; a compressor having a plurality of stages and a plurality of vaporizable liquid delivery devices for providing vaporizable liquid to the compressor, the compressor operable to receive a portion of the first compressed working gas and produce a second compressed working gas; wherein the vaporizable liquid is a fuel; a cooler-condenser fluidly coupled to the compressor, the cooler-condenser operable to receive the second compressed working gas and to cool the second compressed working gas to condense out a majority of the vaporized liquid and to produce a cooled, compressed, dry working gas; a recuperator fluidly coupled to the cooler-condenser for receiving the cooled, compressed, dry working gas, and providing additional thermal energy to produce heated working gas; a combustion chamber fluidly coupled to the recuperator for receiving the heated working gas and a fuel and producing through combustion an exhaust gas; and first expansion turbine fluidly coupled to the combustion chamber for receiving the exhaust gas and expanding the exhaust gas to produce power and a first expanded exhaust gas.

Referring primarily to FIG. 24, A turbo fan engine includes: a fan for receiving a working gas producing a first compressed working gas; a multi-stage compressor having a plurality of vaporizable liquid delivery devices, and operable to receive a portion of the first compressed working gas, and to produce a second compressed working gas, wherein the vaporizable liquid delivery device delivers fuel; a cooler-condenser fluidly coupled to the multi-stage compressor, the cooler-condenser operable to receive the second compressed working gas and condense out a majority of the fuel and to produce a cooled, compressed, dry working gas; a second compressor fluidly coupled to the cooler-condenser operable to receive the cooled, compressed, dry working gas and compress the cooled, compressed, dry working gas; a combustion chamber fluidly coupled to the second compressor for receiving the cooled compressed, dry working gas and producing an exhaust gas; and an expansion turbine fluidly coupled to the combustion chamber for receiving the exhaust gas and expanding the exhaust gas to produce an expanded exhaust gas and energy.

Referring to FIG. 64, a turbo-fan engine having a closed cycle mode, the turbo-fan engine includes: a fan for receiving work gas producing a first working gas; a first compressor turbine fluidly coupled to the fan to receive a portion of the first compressed working gas; a vaporizable liquid delivery device associated with the first compressor and operable to deliver fuel to the first compressor a second compressor fluidly coupled to the first compressor turbine and operable to receive the first compressed working gas and a recycled working gas and produce a second compressed working gas; a recuperator fluidly coupled to the second compressor for receiving the second compressed working gas and supplying thermal energy to produce a heated, second compressed working gas; an expansion chamber fluidly coupled to the recuperator for receiving the heated, second compressed working gas and a fuel and producing an exhaust gas; a first expansion turbine fluidly coupled to a combustion chamber for receiving the exhaust gas and producing a first expanded exhaust gas; a divider fluidly coupled to the first expansion turbine for removing a portion of the exhaust gas corresponding to the heated, second compressed working gas removed in combustion; a first conduit for receiving the remainder of the exhaust gas and delivering the remainder of the exhaust gas to the first compressor; a second conduit fluidly coupled to the recuperator for supplying working as to the second compressor as the recycled working gas; and a nozzle fluidly coupled to the divider for receiving the portion of exhaust gas and a portion of the first working gas and producing propulsion.

Referring to FIG. 26, an open-cycle gas turbine system includes: an inlet operable to receive a working gas; a recuperator fluidly coupled to the inlet for receiving the working gas and providing thermal energy to the working gas to produce a heated working gas; a combustion chamber fluidly coupled to the recuperator for receiving the heated working gas and operable to burn the heated working gas to produce an exhaust gas; a cleaning chamber fluidly coupled to the combustion chamber for receiving the exhaust gas and operable to clean the exhaust gas to produce a cleaned exhaust gas; an expansion turbine fluidly coupled to the cleaning chamber for receiving the cleaned exhaust gas and expanding the cleaned exhaust gas to produced an expanded exhaust gas; a first conduit fluidly coupled to the expansion turbine and fluidly coupled to the recuperator, the first conduit operable to deliver the expanded working gas to the recuperator; a gas washer fluidly coupled to the recuperator for receiving the expanded exhaust gas and producing a cleaned expanded exhaust gas; and a compressor fluidly coupled to the gas washer for receiving the cleaned expanded exhaust gas, the compressor having a vaporizable liquid delivery device and operable to produce a cleaned compressed working gas.

Referring to FIG. 43, an open-cycle gas turbine system includes: an expansion turbine operable to receive a waste heat gas and produce a cooled waste heat gas; a compressor having a vaporizable liquid delivery device and fluidly coupled to the expansion turbine, the compressor operable to receive the cooled waste heat gas and compress the waste heat gas to produce a compressed working gas; a power using device; and a shaft coupled to the expansion turbine and the compressor and operable to provide power to the power using device.

A turbine system for recovering waste, the system includes: an expansion turbine for receiving a waste heat gas and expanding it to produce a cooled waste heat gas; a compressor; a first conduit fluidly coupled to the expansion turbine and the compressor and operable to deliver the cooled waste heat gas from the expansion turbine to the compressor; a first fluid delivery device associated with a first conduit for delivering a vaporizable liquid to the cooled waste heat gas within the first conduit; and a second vaporizable liquid delivery device associated with the compressor for providing a vaporizable liquid to the compressor, wherein the compressor is operable to receive the cooled waste heat gas and produce a compressed working gas.

A turbine system includes: a compressor having a vaporizable liquid delivery device and operable to receive a working gas and to produce a compressed working gas; a medium temperature heat exchanger fluidly coupled to the compressor for receiving the compressed working fluid and providing thermal energy to the compressed working gas to prepare a first heated working gas; a high temperature heat exchanger fluidly coupled to the medium temperature heat exchanger for receiving the first heated working gas and providing additional thermal energy to create an exhaust gas; an expander fluidly coupled to the high temperature heat exchanger for receiving the exhaust gas and expanding it to produce an expanded exhaust gas; an external combustion chamber; a valve fluidly coupled to the external combustion chamber, the expansion turbine and the medium temperature heat exchanger, the valve for receiving the expanded exhaust gas and delivering a first portion to external combustion chamber and a second portion to the medium temperature heat exchanger; wherein the external combustion chamber is operable to combust the first portion of the expanded working gas to develop additional thermal energy in a heated expanded exhaust gas; wherein the high temperature heat exchanger is fluidly coupled to the external combustion chamber for receiving the heated expanded exhaust gas and removal of thermal energy to produce a cooled expanded exhaust gas; wherein the medium temperature heat exchanger is fluidly coupled to the valve for receiving the second portion of the exhaust gas and is further coupled to the high temperature heat exchanger for receiving the cooled expanded exhaust gas.

A turbine system for combined heat and power production, the system includes: a compressor having a vaporizable liquid delivery device and operable to receive a working gas and compress it to form a compressed working gas; a low temperature heat exchanger fluidly coupled to the compressor for receiving the compressed working gas and adding additional thermal energy to form a first heated compressed working gas; a high temperature heat exchanger fluidly coupled to the low temperature heat changer by receiving the first heated compressed working gas and adding additional thermal energy to form a second heated compressed working gas; an expander fluidly coupled to the high temperature heat exchanger for receiving the second heated compressed working gas and expanding it to form an expanded working gas; an external combustion chamber fluidly coupled to the expansion turbine for receiving the expanded working gas and burning the expanded working gas to produce an exhaust gas; and wherein the heat exchanger is fluidly coupled to the external combustion chamber for receiving the heated exhaust gas.

Referring to FIG. 41, An open-cycle turbine system for waste heat recovery, the system includes: a compressor having a vaporizable liquid delivery device for receiving a working gas and compressing it to form a first compressed working gas; a heat exchanger for receiving the first compressed working gas and providing additional thermal energy from the waste heat to created a heated compressed working gas; an expansion turbine fluidly coupled to the heat exchanger for receiving the heated compressed working gas and expanding it to form an expanded working gas; a cooler and condenser fluidly coupled to the expansion turbine for receiving the expanded working gas and condensing out a liquid; and conduit fluidly coupled to the heat exchanger for receiving a waste heat gas.

Referring to FIG. 66, closed-cycle, waste-heat turbine system, the system includes: a compressor having a vaporizable liquid delivery device, operable to receive a working gas and compress the working gas to form a compressed working gas; a heat exchanger coupled to the compressor for receiving the compressed working gas and adding thermal energy from the waste heat to form a heated compressed working gas; an expansion turbine fluidly coupled to the heat exchanger for receiving the heated compressed working gas introducing an expanded working gas; a cooler-condenser fluidly coupled to the expansion turbine for condensing out a liquid to produce a dry expansion working gas and a liquid; and wherein the compressor is fluidly coupled to the cooler-condenser; and wherein the dry compressed working gas is the working gas delivered to the compressor.

Referring to FIG. 47, an open-cycle piston compressor-expansion turbine system, the system includes: a piston compressor having a vaporizable liquid delivery device and operable to receive a working gas and to produce a compressed working gas; a recuperator further coupled to the piston compressor for receiving the compressed working gas and providing thermal energy to produce a heated compressed working gas; a combustion chamber fluidly coupled to the recuperator for receiving the heated compressed working gas and combusting the heated compressed working gas to produce an exhaust gas; an expansion turbine fluidly coupled to the combustion chamber for receiving the exhaust gas and expanding it to produce an expanded exhaust gas, wherein the recuperator is fluidly coupled to the expansion turbine for receiving the expanded exhaust gas and receiving thermal energy from the expanded exhaust gas; a power using device; wherein the expansion turbine is coupled to the power using device to provide power to the power using device.

Referring to FIG. 67, a closed-cycle piston compressor-expansion turbine system, the system includes: a piston compressor having a vaporizable liquid delivery device and operable to receive a working gas and produce a compressed working gas; a recuperator for receiving the compressed working gas and providing thermal energy to produce a heated compressed working gas; a heating unit fluidly coupled to the recuperator for receiving the heated compressed working gas and providing additional thermal energy to produce a twice heated compressed working gas; an expander thoroughly coupled to the heating unit for receiving the twice-heated compressed working gas and expanding it to produce an expanded working gas; wherein the expansion turbine is fluidly coupled to the recuperator for delivering the expanded working gas to the recuperator to provide thermal energy for use in the recuperator and to produce a cooled expanded working gas; a cooler-condenser fluidly coupled to the recuperator for receiving the cooled expanded working gas and condensing out a liquid and to produce the working gas for use in the compressor; a first conduit fluidly coupled to the cooler-condenser and to the piston compressor for operable delivery the working gas from the cooler-condenser to the piston condenser; and a second conduit fluidly coupled to the cooler-condenser and to the vaporizable liquid delivery device operable to deliver the condensed liquid from the cooler-condenser to the vaporizable liquid delivery device.

Referring to FIG. 49, an open-cycle gas turbine system, the system includes: an internal combustion subsystem; and an external combustion subsystem. Continuing to refer to FIG. 49, an open-cycle gas turbine system, the system includes: an internal combustion subsystem; an external combustion subsystem; a first compressor having a vaporizable liquid delivery device and operable to receive a working gas and compress the working gas to form a first compressed working gas; a high temperature heat exchanger fluidly coupled to the first compressor for receiving the first compressed working gas and supplying thermal energy to produce a heated compressed working gas; a combustion chamber fluidly coupled to the high temperature heat exchanger for receiving the heated compressed working gas and producing a first exhaust gas; a first expansion turbine fluidly coupled to the combustion chamber for receiving the first exhaust gas and expanding to produce a first expanded exhaust gas; a low temperature furnace for receiving a solid fuel and operable to produce steam and light hydrocarbons; an auxiliary compressor fluidly coupled to the low temperature furnace and operable to receive from the low temperature furnace gas products produced in the low temperature furnace and compress them to form compressed gas products, wherein the combustion chamber is fluidly coupled to the auxiliary compressor to receive the compressed gas products and to combust the compressed gas products with the heated compressed working gas to form the first exhaust gas; and a high temperature furnace associated with the low temperature furnace and operable to receive a non-pyrolyzed solid fuel from the low temperature furnace and to burn a non-pyrolyzed solid fuel to produce flue gasses, wherein the high temperature heat exchanger is fluidly coupled to the high temperature furnace for receiving the flue gasses and thermal energy.

Referring to FIG. 51, the system just described further includes: a first conduit fluidly coupled to the first expansion turbine for receiving the first expanded exhaust; a splitter further coupled to the first conduit, a splitter operable to split the first expanded exhaust into a first portion and a second portion; a second conduit fluidly coupled to the splitter for receiving the first portion of a first expanded exhaust gas; a first heat exchanger fluidly coupled to the second conduit and operable to receive the first portion of the first expanded exhaust gas and to receive thermal energy from the first portion of the first expanded exhaust gas; a third conduit fluidly coupled to the splitter for receiving the second portion of the first expanded exhaust gas and associated with the high temperature furnace and receiving thermal energy therefrom and associated with the high temperature heat exchanger for providing thermal energy thereto and further coupled to the first heat exchanger for providing thermal energy thereto; a fourth conduit fluidly coupled to the first heat exchanger for receiving the first and second portions of the first expanded exhaust gas and wherein the fourth conduit is associated with the low temperature furnace for providing thermal energy thereto.

Referring to FIG. 54, a closed cycle gas turbine system for carbon dioxide sequestration, the system includes: a compressor having a vaporizable liquid delivery device and operable to receive a CO₂ working gas and compress it to form a compressed working gas; a low temperature heat exchanger operable to receive the compressed working gas and to remove thermal energy to condense a condensable liquid and to produce a dry compressed working gas; a recuperator fluidly coupled to the low temperature heat exchanger for receiving the dry compressed working gas and operable to provide thermal energy to produce a dry, heated working gas; a combustion chamber fluidly coupled to the recuperator for receiving the dry compressing working gas and to combust the working gas with a fuel and oxygen to produce an exhaust gas; an expander fluidly coupled to the combustion chamber for receiving the exhaust gas, expanding it to form an expanded exhaust gas; wherein the recuperator is fluidly coupled to the expansion turbine to receive the expanded exhaust gas and to receive thermal energy from the expanded exhaust gas to produce a cooled expanded exhaust gas; a cooler-condenser fluidly coupled to the recuperator for receiving the cooled expanded exhaust gas and condensing our a condensable liquid to produce a dry expanded exhaust gas; an extraction valve fluidly coupled to the cooler-condenser for receiving the dry expanded exhaust gas and removing a first portion of carbon dioxide and a remaining portion of dry expanded exhaust gas; and wherein the compressor is fluidly coupled to the extraction valve for receiving the remaining dry expanded exhaust gas as the CO₂ working gas.

A closed-cycle turbine system for sequestering carbon dioxide, the system includes: a compressor having a vaporizable liquid delivering device and operable to receive a CO₂ working gas and compress it to form a compressed working gas; a low temperature heat exchanger fluidly coupled to the compressor for receiving the compressed working gas and removing thermal energy to condense a condensable liquid and to form a dry compressed working gas; a extraction valve fluidly coupled to the low temperature heat exchanger for receiving the dry compressed working gas and removing a portion of the carbon dioxide and providing a remaining portion of the dry compressed working gas; a recuperator fluidly coupled to the extraction valve and operable to receive the remaining portion of the dry compressed working gas and providing thermal energy to produce a heated compressed working gas; a combustion chamber fluidly coupled to the recuperator for receiving the heated compressed working gas, fuel, and oxygen and producing a first exhaust gas; an expansion turbine fluidly coupled to the combustion chamber for receiving the first exhaust gas and expanding it to form a first expanded exhaust gas; wherein the recuperators fluidly coupled to the expansion turbine for receiving the first expanded exhaust gas and removing thermal energy to produce a cooled expanded exhaust gas; and a cooler-condenser fluidly coupled to the recuperator for receiving the cooled expanded exhaust gas and condensing out a condensable liquid and producing a dry cooled expanded exhaust gas which is the CO₂ working gas for delivery to the compressor.

Referring to FIG. 57, a closed-cycle gas turbine system for sequestration of carbon dioxide, the system includes: a first compressor fluidly having a vaporizable liquid delivery device and operable to receive a working gas and compress it to form a compressed working gas; a recuperator fluidly coupled to the first compressor for receiving the compressed working gas and supplying thermal energy to produce a heated compressed working gas; a combustion chamber fluidly coupled to the recuperator for receiving the heated combustible working gas and fuel and oxygen and combusting to produce a first exhaust gas; a first expansion turbine fluidly coupled to the combustion chamber for receiving the first exhaust gas and expanding it to form a first expanded exhaust gas; wherein the recuperator is fluidly coupled to the first expansion turbine for receiving the first expanded exhaust gas and receiving thermal energy from the first expanded exhaust gas to produce a first cooled expanded exhaust gas; a second expansion turbine fluidly coupled to the recuperator for receiving the first cooled expanded exhaust gas and expanding the first cooled expanded exhaust gas to produce a second expanded exhaust gas; a cooler-condenser fluidly coupled to the second expansion turbine for receiving the second expanded exhaust gas and condensing out a condensable liquid and producing a dry expanded exhaust gas; a first extraction valve fluidly coupled to the cooler-condenser for receiving the dry expanded exhaust gas and removing at least a portion of the CO₂ and producing a remaining portion of dry expanded exhaust gas; a second valve fluidly coupled to the first extraction valve for receiving the remaining portion of the dry expanded exhaust gas and for receiving a high isentropic exponent gas and mixing the high isentropic exponent gas with the remaining dry expanded exhaust gas to produce the working gas to be supplied to the first compressor.

Referring to FIG. 59, a closed-cycle gas turbine system with carbon dioxide sequestration, the system includes: a compressor turbine having a vaporizable liquid delivery device and operable to receive a working gas and compress the working gas to produce a compressed working gas; an extraction valve fluidly coupled to the compressor for receiving the compressed working gas and removing a sequestration gas and producing a remaining portion of the compressed working gas; a heat exchanger fluidly coupled to the extraction valve for receiving the sequestration gas and produced a first cooled sequestration gas; a first cooler-condenser fluidly coupled to the heat exchanger for receiving the cooled sequestration gas and condensing the sequestration gas and separating a high isentropic exponent gas; a mixer fluidly coupled to the first cooler-condenser receiving the high isentropic exponent gas, fluidly coupled to the extraction valve for receiving the remaining portion of the compressed working gas, and operable to produce a mixed working gas; a recuperator fluidly coupled to the mixer for receiving the mixed working gas and providing thermal energy to produce a heated, mixed working gas; a combustion chamber fluidly coupled to the recuperator for receiving the heated, mixed working gas, a fuel, and oxygen, and producing a first exhaust gas; a first expansion turbine fluidly coupled to the combustion chamber and operable to receive and expand the first exhaust gas to produce a first expanded exhaust gas; wherein the first expansion turbine is fluidly coupled to the recuperator, and wherein the first expanded exhaust gas is delivered to the recuperator to provide thermal energy and to produce a cooled, expanded exhaust gas; a second expansion turbine fluidly coupled to the recuperator for receiving the cooled, expanded exhaust gas and producing a second expanded exhaust gas; a second cooler-condenser fluidly coupled to the second expansion turbine for receiving the second expanded exhaust gas and condensing out a condensable liquid and providing a cooled, twice-expanded exhaust gas; and the compressor fluidly coupled to the second cooler-condenser and wherein the cooled, twice-expanded exhaust gas includes the working gas delivered to the compressor.

Referring to FIG. 61, a closed-cycle gas turbine system with sequestration of a sequestration gas, the system includes: a compressor having a vaporizable liquid delivery device and operable to receive a working gas including the sequestration gas and compressing the working gas to produce a compressed working gas; a low temperature heat exchanger fluidly coupled to the compressor for receiving the compressed working gas and condensing out a first condensable liquid and producing a remaining cooled, compressed working gas; a recuperator fluidly coupled to the low temperature heat exchanger and operable to receive the cooled, compressed working gas and provide thermal energy to create a heated, compressed working gas; a combustion chamber fluidly coupled to the recuperator for receiving the heated, compressed working gas and combusting the heated, compressed working gas with a fuel and oxygen to produce an exhaust gas; an expansion turbine fluidly coupled to the combustion chamber for receiving the exhaust gas and expanding the exhaust gas to produce an expanded exhaust gas; wherein the recuperator is fluidly coupled to the expansion turbine and operable to receive the expanded exhaust gas and to produce a cooled, expanded exhaust gas; a cooler-condenser fluidly coupled to the recuperator for receiving the cooled, expanded exhaust gas and condensing out a second condensable liquid and to produce a dried exhaust gas; an extraction valve fluidly coupled to the cooler-condenser for receiving the dried exhaust gas and removing a portion of the sequestration gas and producing a remaining dried exhaust gas; and wherein the compressor is fluidly coupled to the extraction valve for receiving the remaining dried exhaust gas and wherein the remaining dried exhaust gas is the working gas supplied to the compressor.

Referring to FIG. 62, a closed-cycle gas turbine system with sequestration of sequestration gas, the system includes: a compressor having a vaporizable liquid delivery device and operable to receive a working gas including the sequestration gas and compressing the working gas to produce a compressed working gas; a low temperature heat exchanger fluidly coupled to the compressor for receiving the compressed working gas and condensing out a first condensable liquid and producing a remaining cooled, compressed working gas; an extraction valve fluidly coupled to the low temperature heat exchanger for receiving the cooled, compressed working gas and removing a portion of the sequestration gas and producing a remaining dried, compressed working gas; a recuperator fluidly coupled to the extraction valve and operable to receive the remaining dried, compressed working gas and provide thermal energy to create a heated, compressed working gas; a combustion chamber fluidly coupled to the recuperator for receiving the heated, compressed working gas and combusting the heated, compressed working gas with a fuel and oxygen to produce an exhaust gas; an expansion turbine fluidly coupled to the combustion chamber for receiving the exhaust gas and expanding the exhaust gas to produce an expanded exhaust gas; wherein the recuperator is fluidly coupled to the expansion turbine and operable to receive the expanded exhaust gas and to produce a cooled, expanded exhaust gas; a cooler-condenser fluidly coupled to the recuperator for receiving the cooled, expanded exhaust gas and condensing out a second condensable liquid and to produce a dried exhaust gas; wherein the compressor is fluidly coupled to the cooler-condenser for receiving the dried exhaust gas and wherein the dried exhaust gas is the working gas supplied to the compressor.

Referring to FIG. 55, a closed-cycle liquefaction system for liquefying a liquefiable gas, the system includes: a liquefiable delivery conduit for delivering a liquefiable gas to the system and removing a liquefied gas; a cooler coupled to the liquefiable delivery conduit for removing thermal energy from the liquefiable gas to form a saturated gas mixture; a first condenser-evaporator coupled to the liquefiable delivery conduit downstream of the cooler for condensing the saturated gas mixture to form the liquefied gas; a closed-cycle vaporization engine containing a first working fluid; a second conduit for delivering a cold working gas; a second condenser-evaporator fluidly coupled to the closed-cycle vaporization engine and the second conduit, the second condenser-evaporator operable to receive thermal energy from the first working fluid of the closed-cycle vaporization engine; wherein the first condenser-evaporator is coupled to the closed-cycle vaporization engine for receiving thermal energy from the liquefiable gas in the liquefiable delivery conduit passing through the first condenser-evaporator.

A method for reducing the temperature increase of a working gas during a compression process includes the steps of aspiring the working gas and compressing the working gas. During the compressing, vaporizable liquid droplets are injected into the working gas at a mass rate between approximately 7% and approximately 20% of an aspiration mass rate of the working gas. Substantially all of the vaporizable liquid is allowed to evaporate to vapor, thereby removing thermal energy from the working gas, before continuing compressing. The working gas is substantially saturated with vapor before the end of the compressing. While lowering the end temperature of compressed gas tends to reduce efficiency, providing a means for heating the compressed gas after compression but before it reaches the external source of thermal energy increases efficiency in the cases describe here.

In addition, thermal energy from expanded exhaust may be transferred to the substantially saturated working gas. Fuel may be burned with the working gas to produce exhaust and the exhaust may be expanded. In some cases, the expanded exhaust may be returned for the compressing. The method may also include cooling the substantially saturated working gas thereby condensing substantially all vapor therein; recycling the condensed vapor to be injected; and returning the working gas for the compressing.

In some cases, the vaporizable liquid may be water and the working gas may be air. The working gas may include at least one of ethanol, methanol, fuel, a liquid produced by chlorofluorcarbons, CO₂, and a mixture of fuel and water. The working gas may include at least one of a noble gas, nitrogen, helium, carbon dioxide, oxygen, an inert gas, and air. In some cases the injection rate may be between approximately 7% and approximately 20% of the aspiration rate (in terms of the respective mass flow)

The substantially saturated gas-vapor mixture may be heated using waste heat then expanded and cooled thereby condensing substantially all vapor therein. The condensed vapor may be recycled for use in the injecting. After being cooled, the gas may be returned for compressing.

A system for waste heat recovery includes an expansion turbine, an EVITE compressor, and a generator. The expansion turbine is configured to aspire a gas carrying waste heat and expand the gas. The EVITE compressor is configured to compress the gas with a vaporizable liquid near equilibrium and discharge a substantially saturated gas-vapor mixture. The expansion turbine and the EVITE compressor are mechanically coupled to the generator. In some cases the system includes a cooler-condenser configured to cool the gas-vapor mixture thereby condensing substantially all vapor in the gas-vapor mixture and a pump configured to return the vapor to the EVITE compressor. In some cases, the vaporizable liquid is injected into a conduit transmitting the gas from the expansion turbine to the EVITE compressor. In some cases the pump is also configured to direct the vaporizable liquid to be injected into the conduit.

A system includes an aspiration means for aspiring re-circulated exhaust gas at a first temperature and a first pressure above ambient and a means for supplying a vaporizable liquid at a second temperature and a second pressure. The second pressure and the second temperature are above ambient. The system also includes a first compressing means for compressing the re-circulated exhaust gas with the vaporizable liquid, to evaporate substantially all of the vaporizable liquid to form a substantially saturated gas-vapor mixture. The substantially saturated gas-vapor mixture has a compressed temperature that is substantially equal to the first temperature and a compressed pressure that is higher than the first pressure. The system also includes a pre-heating means for preheating the gas-vapor mixture to a third temperature higher than the compressed temperature, a second compressing means for compressing ambient air to a fourth pressure, and a combustion means for receiving and burning the gas-vapor mixture with the air to produce exhaust. The system also includes an expansion means for expanding the exhaust to the first pressure and channeling the exhaust to the pre-heating means. The pre-heating means uses thermal energy from the exhaust for the preheating. The system also includes a recirculation means for re-circulating a portion of the exhaust to the aspiration means and a splitting means for channeling a second portion of the exhaust to a second expansion means. The second expansion means expands the second portion to ambient pressure.

In some cases, the system includes a second pre-heating means for preheating the air to a fourth temperature that is substantially equal to the third temperature. The second pre-heating means also uses thermal energy from the exhaust for the preheating. In some cases, the system includes a third compressing means for aspiring the compressed air from the second compressing means and compressing the air with vaporizable liquid, to evaporate substantially all of the vaporizable liquid to form a substantially saturated air-vapor mixture. In some cases the third compressing means channels the air-vapor mixture to the first compressing means.

A system including an EVITE compressor, a recuperator, a cooler-condenser, a combustion chamber, and an expansion turbine is included herein. The EVITE compressor is configured to compress a working gas with a vaporizable liquid and discharge a substantially saturated gas-vapor mixture. The recuperator is configured to transfer thermal energy from expanded exhaust to the substantially saturated gas-vapor mixture. The cooler-condenser is configured to extract a variable amount of thermal energy from at least one of the substantially saturated gas-vapor mixture, the expanded exhaust before it transfers thermal energy to the substantially saturated gas-vapor mixture, and the expanded exhaust after it transfers thermal energy to the substantially saturated gas-vapor mixture. The combustion chamber is fluidly coupled to the recuperator and configured to receive the substantially saturated working gas from the recuperator and produce exhaust. The expansion turbine is fluidly coupled to the combustion chamber, wherein the expansion turbine is configured to produce the expanded exhaust. The system may also include a pump configured to return condensed vapor from the cooler-condenser to the compressor for use as vaporizable liquid; and a recirculation conduit configured to channel the expanded exhaust to the compressor for compression as the working gas.

A system including an EVITE compressor, a recuperator, a high temperature heat exchanger, a first expansion turbine, a second expansion turbine, and a generator is also included. The EVITE compressor is configured to compress a working gas with a vaporizable liquid and discharge a substantially saturated gas-vapor mixture. The recuperator is fluidly coupled to the compressor and configured to preheat the substantially saturated working gas to a first temperature substantially equal to a third temperature. The recuperator is configured to transfer thermal energy from the expanded working gas to the substantially saturated working gas. The high temperature heat exchanger is fluidly coupled to the recuperator and configured to receive the pre-heated working gas from the recuperator and heat the working gas to a second temperature higher than the first temperature. The first expansion turbine is fluidly coupled to the high temperature heat exchanger. The first expansion turbine is configured to expand the working gas to a first pressure and the third temperature and to channel the expanded working gas to the recuperator. The second expansion turbine is in fluid communication with the recuperator and is configured to expand the expanded working gas to a second pressure lower than the first pressure. The compressor, the first turbine, and the second turbine are mounted on a common shaft and drive the generator. A cooler-condenser may be included to condense vapor and a pump configured to return condensed vapor from the cooler-condenser to the compressor for use as vaporizable liquid.

A turbo fan engine system is included. A fan is configured to blow air through a manifold. The air includes a bypass portion and a combustion portion. The manifold contains an auxiliary compressor, a closed-cycle engine, an auxiliary expansion turbine, and a nozzle. The auxiliary compressor is configured to compress the combustion portion. The closed-cycle engine includes an EVITE compressor, a recuperator, a combustion chamber, an expansion turbine, a cooler-condenser, a pump, and a recirculation conduit. The auxiliary expansion turbine is configured to receive and expand a portion of the expanded exhaust corresponding to the combustion portion. The nozzle is configured to receive and accelerate the bypass portion and the portion of the expanded exhaust from the auxiliary expansion turbine. The EVITE compressor is configured to compress a working gas with a vaporizable liquid and discharge a substantially saturated vapor-gas mixture. The recuperator is configured to heat the vapor-gas mixture using thermal energy from expanded exhaust. The combustion chamber is configured to receive the vapor-gas mixture from the recuperator and the combustion portion from the auxiliary compressor, and to burn the vapor-gas mixture and the combustion portion with fuel thereby producing exhaust. The expansion turbine is configured to expand the exhaust. The cooler-condenser is configured to receive a majority of the expanded exhaust from the expansion turbine and to cool the majority using the bypass portion thereby condensing vapor from the expanded exhaust. The pump is configured to return the condensed vapor to the EVITE compressor as vaporizable liquid. The recirculation conduit is configured to return the majority to the EVITE compressor as the working gas.

Another system includes a fan configured to blow air through a manifold. The air includes a bypass portion and a working portion. The manifold contains an EVITE compressor, a cooler-condenser, a pump, a recuperator, a combustion chamber, an expansion turbine, and a nozzle. The EVITE compressor is configured to compress the working portion with a vaporizable fuel and discharge a substantially saturated fuel vapor-gas mixture. The cooler-condenser is cooled by the bypass portion so that fuel vapor in the fuel vapor-gas mixture is condensed. The pump is configured to return the condensed fuel vapor to the compressor for injection as vaporizable fuel. The recuperator is configured to heat the working portion using thermal energy from expanded exhaust. The combustion chamber is configured to burn fuel with the working portion thereby producing exhaust. The expansion turbine is configured to expand the exhaust and to channel the expanded exhaust to the recuperator. The nozzle is configured to receive the bypass portion and expanded exhaust.

A system includes a fan configured to blow air through a manifold. The air includes a bypass portion and a working portion. The manifold contains an EVITE compressor, a cooler-condenser, a pump, a recuperator, a combustion chamber, a first expansion turbine, a second expansion turbine, and a nozzle. The EVITE compressor is configured to compress the working portion with a vaporizable fuel and discharge a substantially saturated fuel vapor-gas mixture. The cooler-condenser is configured to cool the fuel vapor-gas mixture thereby condensing a majority of fuel vapor in the fuel vapor-air mixture and is cooled by the bypass portion. The pump is configured to return the condensed fuel vapor to the compressor for injection as vaporizable fuel. The recuperator is configured to transfer heat from expanded exhaust to the cooled fuel vapor-air mixture. The combustion chamber has a fuel injector configured to inject fuel into the combustion chamber and is configured to burn the fuel vapor-air mixture with injected fuel thereby producing exhaust. The first expansion turbine is configured to expand the exhaust and to channel the expanded exhaust to the recuperator. The second expansion turbine is configured to further expand the expanded exhaust after the transfer of heat in the recuperator. The nozzle is configured to receive expanded exhaust from the second expansion turbine and the bypass portion.

A turbine system includes a fan configured to blow air through a manifold. The air includes a bypass portion and a working portion. The manifold contains an EVITE compressor, a cooler-condenser, a pump, a second compressor, a combustion chamber, an expansion turbine, and a nozzle. The EVITE compressor is configured to compress the working portion with a vaporizable fuel and discharge a substantially saturated fuel vapor-gas mixture. The cooler-condenser is configured to cool the fuel vapor-gas mixture thereby condensing a majority of fuel vapor in the fuel vapor-air mixture and is cooled by the bypass portion. The pump is configured to return the condensed fuel vapor to the compressor for injection as vaporizable fuel. The second compression turbine is configured to re-compress the fuel vapor-air mixture. The second compressor increases the temperature at the inlet of the combustion chamber, thereby increasing efficiency of the thermodynamic cycle by increasing the combustion temperature. The combustion chamber has a fuel injector configured to inject fuel into the combustion chamber and is configured to burn the fuel vapor-air mixture with injected fuel thereby producing exhaust. The expansion turbine is configured to expand the exhaust. The nozzle is configured to receive the bypass portion and expanded exhaust.

A system includes an EVITE compressor, a cooler-condenser, a pump, a second compressor, a combustion chamber, and an expansion turbine. The EVITE compressor is configured to compress a working gas with a vaporizable liquid and discharge a substantially saturated gas-vapor mixture. The cooler-condenser is configured to cool the gas-vapor mixture thereby condensing substantially all vapor in the gas-vapor mixture and drying the working gas. The pump is configured to return the vapor to the EVITE compressor. The second compressor is to aspire and compress the dried working gas. The second compressor increases the temperature at the inlet of the combustion chamber, thereby increasing efficiency of the thermodynamic cycle by increasing the combustion temperature. The combustion chamber is fluidly coupled to the second compressor and configured to burn the working gas with fuel to produce exhaust. The expansion turbine is configured to expand the exhaust. In some cases the exhaust may be returned to the EVITE compressor as the working gas.

A system including an EVITE compressor, a recuperator, an external heat source, an expansion turbine, a cooler-condenser, a pump, and a recirculation conduit is included. The EVITE compressor is configured to compress a working gas with a vaporizable liquid and discharge a substantially saturated gas-vapor mixture. The recuperator is configured to pre-heat the gas-vapor mixture using thermal energy from an expanded gas-vapor mixture. The external heat source is fluidly coupled to the recuperator and configured to receive and further heat the gas-vapor mixture from the recuperator. The expansion turbine is fluidly coupled to the external heat source and configured to expand the gas-vapor mixture from the external heat source. The cooler-condenser is configured to cool the expanded gas-vapor mixture thereby condensing substantially all vapor in the gas-vapor mixture. The pump is configured to return the condensed vapor to the compressor for injection as vaporizable liquid. The recirculation conduit configured to channel the gas to the compressor for compression as the working gas.

In some cases, the external heat source includes a heat exchanger. In some cases the system includes a first cooler-condenser configured to extract a variable amount of thermal energy from the substantially saturated gas-vapor mixture before passing the gas-vapor mixture to the recuperator.

In some cases, the external heat source includes a combustion chamber configured to burn a hydrocarbon fuel with substantially pure oxygen and the working gas thereby producing additional CO₂ and water and the working gas includes CO₂. The system may also include a valve configured to divert a portion of the gas-vapor mixture received from the cooler-condenser and corresponding to the additional CO₂ to a liquefying engine. In some cases, the valve may be configured to divert a portion of the gas-vapor mixture received from the first cooler-condenser and corresponding to the additional CO₂ to storage.

In some cases, system includes a second compressor configured to receive and compress the substantially saturated gas-vapor mixture from the recuperator and the external heat source includes a combustion chamber. The second compressor increases the temperature at the inlet of the combustion chamber, thereby increasing efficiency of the thermodynamic cycle by increasing the combustion temperature. In some cases the system also includes a second expansion turbine configured to expand the expanded gas-vapor mixture after thermal energy from the expanded gas-vapor mixture has been transferred to the substantially saturated gas-vapor mixture in the recuperator.

A system including an EVITE compressor, a recuperator, a combustion chamber, an expansion turbine, a cooler-condenser, a pump, an outlet, and a separation valve is included. The EVITE compressor is configured to compress CO₂ with water and discharge a substantially saturated mixture. The recuperator is configured to pre-heat the gas-vapor mixture using thermal energy from an expanded mixture. The combustion chamber is fluidly coupled to the recuperator and configured to receive the mixture from the recuperator and burn it with a hydrocarbon fuel and O₂ to produce additional CO₂ and additional water. The expansion turbine is fluidly coupled to the combustion chamber and is configured to produce the expanded mixture from the mixture and the additional CO₂ and additional water. The cooler-condenser is configured to cool the expanded mixture thereby condensing substantially all of the water vapor in the expanded mixture. The pump configured to return a portion of the condensed water vapor to the compressor to be compressed with the CO₂. The outlet is configured to discharge a remaining portion of the condensed water vapor corresponding to the additional water. The separation valve is configured to return a part of the working gas to the compressor and to divert a second part of the working gas corresponding to the additional CO₂ to a liquefaction engine.

A system including an EVITE compressor, an extraction valve, a recuperator, a combustion chamber, an expansion turbine, a cooler-condenser, and a pump is included. The EVITE compressor is configured to compress a working gas with a vaporizable liquid and discharge a substantially saturated mixture. The extraction valve is configured receive the mixture from the compressor and to channel a first part of the mixture to the recuperator and to divert a second part of the mixture corresponding to additional CO₂. The recuperator is configured to pre-heat the mixture using thermal energy from expanded working gas. The combustion chamber is fluidly coupled to the recuperator and configured to receive the mixture from the recuperator and burn it with a hydrocarbon fuel and O₂ to produce the additional CO₂ and water. The expansion turbine is fluidly coupled to the combustion chamber and configured to produce the expanded working gas from the mixture and the additional CO₂ and water. The cooler-condenser is configured to condense substantially all water vapor in the expanded working gas after the thermal energy from the expanded working gas is used in the recuperator. The pump configured to return at least some of the condensed water vapor to the compressor to be compressed. This system allows for liquefaction at or near ambient temperature and does not require an external compressor.

In some cases the working gas includes CO₂. In some cases the second part is diverted to storage. In some cases the working gas includes CO₂ and a gas having a high isentropic exponent. In some cases the second part is diverted to a heat exchanger configured to cool the second part and to direct the cooled second part to a condenser. The condenser is configured to condense substantially all CO₂ from the second part and return a remaining portion of the second part to the first part for pre-heating in the recuperator.

A system including an EVITE compressor, a recuperator, an external heat source, a first expansion turbine, a second expansion turbine, a cooler-condenser, and a pump is included. The EVITE compressor is configured to compress CO₂ with water and discharge a substantially saturated mixture. The recuperator is configured to pre-heat and discharge the substantially saturated mixture using thermal energy from the mixture expanded to an intermediate pressure. The external heat source is configured to add external thermal energy to the mixture discharged from the recuperator. The first expansion turbine is configured to expand the mixture discharged from the external heat source to the intermediate pressure. The second expansion turbine is configured to expand the mixture from the intermediate pressure to a base pressure. The base pressure is a pressure at which the working gas enters the compressor and is less than the intermediate pressure. The cooler-condenser is configured to cool the mixture discharged from the second expansion turbine thereby condensing substantially all vapor in the mixture. The pump is configured to return a portion of the condensed vapor to the compressor.

In some cases, the external heat source is a combustion chamber burning a hydrocarbon fuel with the working gas thereby producing CO₂ and water. An extraction valve configured to direct a sequestration portion of the mixture corresponding to the CO₂ produced in the combustion chamber to a liquefaction engine may be included. The liquefaction engine removes the CO₂ from the sequestration portion and returns the sequestration portion to the EVITE compressor as the working gas

A compressor system is also included. The compressor system includes a means for aspiring a gas at a predetermined rate, a means for supplying an amount of a vaporizable liquid to the gas, wherein the amount of the vaporizable liquid is based, at least in part, on the predetermined rate, a means for compressing the gas with the vaporizable liquid to evaporate substantially all of the vaporizable liquid to form a substantially saturated gas-vapor mixture, a means for cooling the gas-vapor mixture to condense substantially all vapor from the gas-vapor mixture to form a compressed gas, and a means for storing and buffering the compressed gas.

A method includes aspiring a working gas, supplying an amount of a vaporizable liquid to the gas, compressing the gas with the vaporizable liquid to evaporate substantially all of the vaporizable liquid to form a substantially saturated gas-vapor mixture, preheating the gas-vapor mixture using waste heat, supplying external thermal energy to the gas-vapor mixture, and expanding the gas-vapor mixture. The amount of the vaporizable liquid is based, at least in part, on the predetermined rate. The latent heat of vaporization of the amount of vaporizable liquid is between approximately 30% and approximately 50% of the external thermal energy.

A gas turbine system includes a means for compressing a gas with a vaporizable liquid to evaporate substantially all of the vaporizable liquid to form a substantially saturated gas-vapor mixture. The substantially saturated gas-vapor mixture has a compressed temperature. A first means for preheating the gas-vapor mixture to a first temperature, a second means for pre-heating the gas-vapor mixture to a second temperature, and a means for expanding the gas-vapor mixture to a third temperature are included. The third temperature is between the compressed temperature and the second temperature. A means for splitting the expanded gas-vapor mixture into a first stream and a second stream is included. The first stream transfers energy to the gas-vapor mixture in the first means. The system includes a means for supplying external thermal energy to the second stream such that the second stream reaches a fourth temperature. The fourth temperature is greater than each of the compressed temperature, the first temperature, the second temperature, and the third temperature. The second stream transfers a first portion of thermal energy to the gas-vapor mixture in the second means and a second portion of thermal energy to the gas-vapor mixture in the first means. A means for removing vapor from the gas vapor mixture before pre-heating it in the first means may be included.

An EVITE compressor includes a means for aspiring a gas, a plurality of compressing means for compressing the gas, and a plurality of holding means, between respective pairs of compressing means, for holding significantly more vaporizable liquid than the gas can absorb. Each holding means includes a means for saturating the working gas with the vaporizable liquid. The compressor also includes a means of passing the gas through the holding means at a predetermined rate and a means of discharging the gas after passing the gas through all of the compressing means and the holding means.

A system comprising an EVITE compressor, a recuperator, an external heat source, and an expansion turbine is included. The EVITE compressor is configured to aspire a working gas at a first pressure and a first temperature, compress the working gas with a vaporizable liquid, and discharge a substantially saturated gas-vapor mixture. The recuperator is configured to preheat the substantially saturated gas-vapor mixture discharged from the EVITE compressor using thermal energy from gas-vapor mixture expanded to the base pressure. The external heat source is configured to add external thermal energy to the pre-heated gas-vapor mixture. The expansion turbine is configured to expand the gas-vapor mixture to a base pressure.

The system also may also include a means for draining vapor from the gas-vapor mixture leaving a remaining portion of the gas-vapor mixture, and a recirculation conduit configured to channel the remaining portion of the gas-vapor mixture to the compressor for compression as the working gas. The means for draining vapor from the system may include cooler-condenser configured to cool the gas-vapor mixture discharged from the expansion turbine thereby condensing substantially all vapor in the gas-vapor mixture and a pump configured to return a portion of the condensed vapor to the compressor. The first pressure may be the base pressure and may be above ambient pressure. The first temperature may be above ambient temperature.

The external heat source may be a combustion chamber and the system may also include a second compression turbine configured to receive the pre-heated gas-vapor mixture from the recuperator. The system may also include a second expansion turbine to expand the gas vapor mixture from the base pressure to ambient pressure.

In some cases the external heat source may be a combustion chamber and the EVITE compressor may include a screw compressor or a piston compressor. In some cases the base pressure may equal the first pressure.

The system may also include a second expansion turbine, a cooler-condenser, a pump, and a liquefier. The external heat source may be a combustion chamber. The cooler-condenser may be configured to receive the gas-vapor mixture having transferred thermal energy to the substantially saturated gas-vapor mixture, to cool the gas-vapor mixture to a second temperature approximately equal to the ambient temperature, and to condense substantially all vapor in the gas-vapor mixture. The pump may be configured to return a portion of the condensed vapor to the EVITE compressor. The second expansion turbine may be configured to receive dried gas from the cooler-condenser and to expand the gas to ambient pressure and to cool the gas to a third temperature below ambient temperature. The gas may be returned to the EVITE compressor. The liquefier may be configured to liquefy a second gas by transferring energy from the second gas to the expanded gas at the third temperature.

The system may also include a second expansion turbine, a cooler-condenser, a pump, and a liquefier. The external heat source may be a heat exchanger. The first pressure may be ambient pressure. The first temperature may be ambient temperature. The base pressure may be above ambient pressure. The cooler-condenser may be configured to receive the gas-vapor mixture having transferred thermal energy to the substantially saturated gas-vapor mixture, to cool the gas-vapor mixture to a second temperature approximately equal to the ambient temperature, and to condense substantially all vapor in the gas-vapor mixture. The pump may configured to return a portion of the condensed vapor to the EVITE compressor. The second expansion turbine may be configured to receive dried gas from the cooler-condenser and to expand the gas to ambient pressure and to cool the gas to a third temperature below ambient temperature. The liquefier may be configured to liquefy a second gas by transferring energy from the second gas to the expanded gas at the third temperature.

The system may also include a second expansion turbine, a cooler-condenser, and a pump. The external heat source may be a heat exchanger. The base pressure may be above the first pressure. The second expansion turbine may be configured to receive the gas-vapor mixture having transferred thermal energy to the substantially saturated gas-vapor mixture and to expand the gas to the first pressure. The cooler-condenser may be configured to receive the gas-vapor mixture from the second expansion turbine and to condense substantially all vapor in the gas-vapor mixture. The pump may be configured to return a portion of the condensed vapor to the EVITE compressor.

A system includes a recuperator, a combustion chamber, a cleaning chamber, an expansion turbine, a gas washer, and an EVITE compressor. The recuperator is configured to preheat ambient air using thermal energy from expanded exhaust. The combustion chamber is fluidly coupled to the recuperator and configured to burn the air with fuel to produce exhaust. The cleaning chamber is coupled to the combustion chamber. The expansion turbine is configured to expand cleaned exhaust from the cleaning chamber. The gas washer is configured to receive the expanded exhaust and remove additional impurities from the expanded exhaust. The EVITE compressor is configured to compress the expanded exhaust with a vaporizable liquid, and discharge a gas-vapor mixture at ambient temperature.

A system includes an EVITE compressor, a high temperature heat exchanger, an internal combustion chamber, an expansion turbine, and an external heat source. The EVITE compressor is configured to aspire a working gas, compress the working gas with a vaporizable liquid to a predetermined pressure, and discharge a substantially saturated gas-vapor mixture. The high temperature heat exchanger is fluidly coupled to the EVITE compressor and configured to heat the working gas using thermal energy an external heat source. The internal combustion chamber is fluidly coupled to the heat exchanger and configured to produce exhaust. The expansion turbine is configured to expand the exhaust. The external heat source includes a low temperature furnace for partial pyrolysis of solid fuel, a high temperature furnace, and an auxiliary compressor. The low temperature furnace is configured to discharge gas products of the pyrolysis. The high temperature furnace is configured to receive the solid fuel remaining after pyrolysis and burn the remaining solid fuel with air thereby producing the thermal energy used by the high temperature heat exchanger. The auxiliary compressor is configured to receive the gas products, compress the gas products to the predetermined pressure, and discharge the gas products to the combustion chamber for burning with the working gas.

A mixed cycle system includes an open cycle system and a closed-cycle engine. The open cycle system includes an auxiliary compressor and an auxiliary expansion turbine. The auxiliary compressor is configured to compress ambient air and supply it to a mixer. The auxiliary expansion turbine is configured to discharge a portion of exhaust. The closed-cycle engine includes the mixer and an EVITE compressor, a recuperator, a second compressor, a combustion chamber, a first expansion turbine, a second expansion turbine, and a cooler-condenser. The EVITE compressor is configured to compress a working gas with a vaporizable liquid and discharge a substantially saturated vapor-gas mixture. The recuperator is configured to heat the vapor-gas mixture using thermal energy from remaining expanded exhaust. The mixer is configured to receive the compressed air from the auxiliary compressor and the vapor-gas mixture from the recuperator and discharge a second mixture. The second compressor is configured to compress to second mixture. The combustion chamber is configured to receive the second mixture from the second compressor and burn the second mixture with fuel thereby producing exhaust. The first expansion turbine is configured to expand the exhaust and discharge the portion of exhaust to the auxiliary expansion turbine and channel the remaining expanded exhaust to the recuperator. The second expansion turbine is configured to expand the remaining expanded exhaust having transferred thermal energy in the recuperator. The cooler-condenser is configured to cool the remaining expanded exhaust from the second expansion turbine thereby condensing substantially all vapor in the remaining expanded exhaust, and configured to return the remaining expanded exhaust to the EVITE compressor as the working gas.

A mixed cycle system includes an open cycle system and a closed-cycle engine. The open cycle system includes an auxiliary piston compressor and an auxiliary expansion turbine. The auxiliary piston compressor is configured to compress ambient air and supply it to an EVITE piston compressor. The auxiliary expansion turbine is configured to discharge a portion of exhaust. The closed-cycle engine includes the EVITE piston compressor, a recuperator, a combustion chamber, an expansion turbine, and a cooler-condenser. The EVITE piston compressor is configured to compress a working gas with a vaporizable liquid and discharge a substantially saturated vapor-gas mixture. The recuperator is configured to heat the vapor-gas mixture using thermal energy from remaining expanded exhaust. The combustion chamber is configured to receive the vapor-gas mixture from the recuperator and burn the vapor-gas mixture with fuel thereby producing exhaust. The expansion turbine is configured to expand the exhaust and discharge the portion of exhaust to the auxiliary expansion turbine and channel the remaining expanded exhaust to the recuperator. The cooler-condenser is configured to cool the remaining expanded exhaust from the expansion turbine thereby condensing substantially all vapor in the remaining expanded exhaust and configured to return the remaining expanded exhaust to the EVITE piston compressor as the working gas

The present invention and its advantages have been disclosed in the context of certain illustrative, non-limiting embodiments. The illustrative descriptions above are not intended to be exhaustive or to limit the invention to the precise forms disclosed. Moreover, it should be understood that various changes, substitutions, permutations, and alterations can be made without departing from the scope of the invention as defined by the appended claims. It will be appreciated that any feature that is described in a connection to any one embodiment may also be applicable to any other embodiment. 

1. An open-cycle gas turbine system for producing power and optionally heat, the system comprising: a compressor for receiving a working gas and compressing the working gas to produce a compressed working gas; a vaporizable liquid delivery device associated with the compressor for delivering a vaporizable liquid to the working gas; a heat exchanger fluidly coupled to the compressor for receiving the compressed working gas and cooling the compressed working gas to produce a cooled, compressed working gas; a recuperator for receiving the cooled, compressed working gas from the heat exchanger and adding thermal energy to produce a heated, compressed working gas; a combustion chamber fluidly coupled to the recuperator for receiving the heated, compressed working gas from the recuperator and combusting the heated, compressed working gas to produce an exhaust gas; an expansion turbine fluidly coupled to the combustion chamber for receiving the exhaust gas and expanding the exhaust gas to develop power and to produce an expanded exhaust gas; and wherein the recuperator is fluidly coupled to the expansion turbine for receiving the expanded exhaust gas.
 2. The system of claim 1 wherein the compressor and vaporizable liquid delivery device are operable to substantially saturate the compressed working gas.
 3. The system of claim 1 wherein the heat exchanger is operable to condense out a condensable liquid from the compressed working gas.
 4. The system of claim 1 wherein the heat exchanger is operable to condense out between 0% and 100% of a condensable liquid from the compressed working gas.
 5. The system of claim 1 wherein the heat exchanger is operable to condense out a condensable liquid from the compressed working gas to form a condensed liquid; and further comprising a conduit fluidly coupled to the heat exchanger for removing condensed liquid.
 6. The system of claim 1 further comprising: a coolant delivery conduit fluidly coupled to the heat exchanger for delivering a coolant; and a coolant controller for controlling an amount of coolant delivered to the heat exchanger.
 7. The system of claim 1 further comprising: a coolant delivery conduit fluidly coupled to the heat exchanger for delivering a coolant; a coolant controller for controlling an amount of coolant delivered to the heat exchanger; and wherein the heat exchanger is operable to condense out between 0% and 100% of a condensable liquid from the compressed working gas in response to the amount of coolant delivered by the coolant controller.
 8. An open-cycle gas turbine system for producing power and optionally heat, the system comprising: a compressor for receiving a working gas and compressing the working gas to produce a compressed working gas; a vaporizable liquid delivery device associated with the compressor for delivering a vaporizable liquid to the working gas; a heat exchanger fluidly coupled to the compressor for receiving the compressed working gas and cooling the compressed working gas to produce a cooled, compressed working gas; a recuperator for receiving the cooled, compressed working gas from the heat exchanger and adding thermal energy to produce a heated, compressed working gas; a combustion chamber fluidly coupled to the recuperator for receiving the heated, compressed working gas from the recuperator and combusting the heated, compressed working gas to produce an exhaust gas; an expansion turbine fluidly coupled to the combustion chamber for receiving the exhaust gas and expanding the exhaust gas to develop power and to produce an expanded exhaust gas; and wherein the recuperator is fluidly coupled to the expansion turbine for receiving the expanded exhaust gas.
 9. The system of claim 8 wherein the compressor and vaporizable liquid delivery device are operable to substantially saturate the compressed working gas.
 10. The system of claim 8 wherein the heat exchanger is operable to condense out a condensable liquid from the compressed working gas.
 11. The system of claim 8 wherein the heat exchanger is operable to condense out between 0% and 100% of a condensable liquid from the compressed working gas.
 12. The system of claim 8 wherein the heat exchanger is operable to condense out a condensable liquid from the compressed working gas to form a condensed liquid; and further comprising a conduit fluidly coupled to the heat exchanger for removing condensed liquid.
 13. The system of claim 8 further comprising: a coolant delivery conduit fluidly coupled to the heat exchanger for delivering a coolant; and a coolant controller for controlling an amount of coolant delivered to the heat exchanger.
 14. The system of claim 8 further comprising: a coolant delivery conduit fluidly coupled to the heat exchanger for delivering a coolant; a coolant controller for controlling an amount of coolant delivered to the heat exchanger; and wherein the heat exchanger is operable to condense out between 0% and 100% of a condensable liquid from the compressed working gas in response to the amount of coolant delivered by the coolant controller.
 15. A method of producing power with an open-cycle gas turbine, the method comprising the steps of: compressing a working gas to produce a compressed working gas; wherein the step of compressing a working gas comprises delivering a vaporizable liquid to the working gas; cooling the compressed working gas in a heat exchanger to produce a cooled, compressed working gas; adding thermal energy in a recuperator to the cooled, compressed working gas to produce a heated, compressed working gas; combusting the heated, compressed working gas in a combustion chamber o produce an exhaust gas; expanding the exhaust gas in an expansion turbine to develop power and to produce an expanded exhaust gas; and supplying thermal energy to the recuperator from the expanded exhaust gas.
 16. The method of claim 15 wherein the step of compressing a working gas further comprises substantially saturating the working gas.
 17. The system of claim 15 further comprising: delivering a coolant to the heat exchanger; and controlling an amount of coolant delivered to the heat exchanger.
 18. The system of claim 15 further comprising: delivering a coolant to the heat exchanger; controlling an amount of coolant delivered to the heat exchanger; and wherein the heat exchanger is operable to condense out between 0% and 100% of a condensable liquid from the compressed working gas in response to the amount of coolant delivered by the coolant controller.
 19. An open-cycle gas turbine system, the system comprising: a compressor for receiving a working gas and compressing the working gas to produce a compressed working gas; a vaporizable liquid delivery device associated with the compressor for delivering liquid droplets to the working gas; a recuperator fluidly coupled to the compressor for receiving the compressed working gas from the compressor and delivering thermal energy to the compressed working gas to produce a heated, compressed working gas; a combustion chamber fluidly coupled to the recuperator for combusting the heated, compressed working gas to produce an exhaust gas; an expansion turbine fluidly coupled to the combustion chamber for receiving the exhaust gas and removing energy from the heat exhaust gas to produce an expanded exhaust gas; a heat exchanger fluidly coupled to the expansion turbine for receiving the expanded exhaust gas and removing thermal energy from the expanded exhaust gas to produce a cooled, expanded exhaust gas; and a conduit associated with the heat exchanger for receiving the cooled, expanded exhaust gas and delivering the cooled, expanded exhaust to the recuperator.
 20. The system of claim 19 wherein the compressor and vaporizable liquid delivery device are operable to substantially saturate the compressed working gas.
 21. The system of claim 19 wherein the compressor and vaporizable liquid delivery device are operable to substantially saturate the compressed working gas.
 22. An open-cycle gas turbine system, the system comprising: a first compressor having a vaporizable liquid delivery device, the first compressor for receiving a working gas and compressing the working gas to form a compressed working gas; a recuperator fluidly coupled to the compressor, the recuperator for receiving the compressed working gas and providing thermal energy to the compressed working gas to produce a heated, compressed working gas; a first expansion turbine fluidly coupled to the recuperator for receiving the heated, compressed working gas and operable to expand the heated, compressed working gas to produce energy and a once-expanded working gas; a conduit for delivering the once-expanded working gas from the first expansion turbine to the recuperator; and a second expansion turbine fluidly coupled to the recuperator for receiving the once-expanded working gas and operable to expand the once-expanded working gas to produce energy and to produce a twice-expanded working gas.
 23. The system of claim 22 wherein the compressor and vaporizable liquid delivery device are operable to substantially saturate the compressed working gas.
 24. The system of claim 22 further comprising a heat exchanger fluidly coupled to the recuperator and fluidly coupled to the first expansion turbine, the heat exchanger operable to receive the heated, compressed working gas from the recuperator and further heat the heated, compressed working gas.
 25. The system of claim 22 further comprising a cooler-condenser fluidly coupled to the second expansion turbine for receiving the twice-expanded working gas and condensing out a vaporizable liquid from the twice-expanded working gas.
 26. The system of claim 25 wherein the cooler-condenser is fluidly coupled to the vaporizable liquid delivery device.
 27. An open-cycle gas turbine system, the system comprising: a compressor having a vaporizable liquid delivery device, and wherein the compressor is operable to receive a working gas and compress the working gas to produce a compressed working gas; a recuperator fluidly coupled to the compressor for receiving the working gas and adding thermal energy to produce a once-heated, compressed working gas; a second compressor fluidly coupled to the recuperator for receiving the once-heated, compressed working gas and further compressing the once-heated, compressed working gas to produce a twice-compressed working gas; a combustion chamber fluidly coupled to the second compressor for receiving the twice-compressed working gas and combusting the twice-compressed working gas to produce an exhaust gas; a expansion turbine fluidly coupled to the combustion chamber for receiving the exhaust gas and expanding the exhaust gas to produce an expanded exhaust gas; and a conduit fluidly coupled between the recuperator and the expansion turbine for delivering the expanded working gas from the expansion turbine to the recuperator wherein the expanded working gas provides thermal energy.
 28. The system of claim 27 wherein the compressor and vaporizable liquid delivery device are operable to substantially saturate the compressed working gas.
 29. The system of claim 27 wherein the compressor and vaporizable liquid delivery device are operable to fully saturate the compressed working gas.
 30. An open-cycle gas turbine system, the system comprising: a first compressor for receiving a working gas, the first compressor having a vaporizable liquid delivery device and operable to produce a compressed working gas; a cooler-condenser fluidly coupled to the first compressor for receiving the compressed working gas and cooling the compressed working gas to produce a condensed liquid and a cooled, compressed working gas; a conduit for delivering the condensed liquid from the cooler-condenser to the vaporizable liquid delivery device; a second compressor fluidly coupled to the cooler-condenser for receiving the cooled compressed working gas and operable to produce a twice-compressed working gas; a combustion chamber fluidly coupled to the second compressor for receiving the twice-compressed working gas and combusting the twice-compressed working gas to produce an exhaust gas; and an expansion turbine fluidly coupled to the combustion chamber for receiving the exhaust gas and operable to expand the exhaust gas to develop energy and produce an expanded exhaust gas.
 31. The system of claim 30 wherein the first compressor and vaporizable liquid delivery device are operable to substantially saturate the working gas.
 32. The system of claim 30 wherein the first compressor and vaporizable liquid delivery device are operable to fully saturate the working gas.
 33. An open-cycle gas turbine system, the system comprising: a first compressor having a vaporizable liquid delivery device and operable to receive a working gas and to compress the working gas to produce a compressed working gas; a recuperator fluidly coupled to the first compressor for receiving the compressed working gas and operable to provide thermal energy to the working gas to produce heated, compressed working gas; a second compressor fluidly coupled to the recuperator for receiving the heated, compressed working gas from the recuperator and compressing the heated, compressed working gas to produce a twice-compressed working gas; a combustion chamber fluidly coupled to the second compressor for receiving the twice-compressed working gas and combusting the twice-compressed working gas to produce an exhaust gas; a first expansion turbine fluidly coupled to the combustion chamber for receiving the exhaust gas and operable to produce a once-expanded exhaust gas; a conduit fluidly coupled to the recuperator and the first expansion turbine, the conduit for delivering the once-expanded exhaust gas from the first expansion turbine to the recuperator; wherein the recuperator is further operable to receive thermal energy from the once-expanded exhaust gas and to produce a cooled, once-expanded exhaust gas; and a second expansion turbine fluidly coupled to the recuperator for receiving the cooled, once-expanded exhaust gas and expanding the cooled, once-expanded exhaust gas to produced a twice-expanded exhaust gas and energy.
 34. The system of claim 33 wherein the compressor and vaporizable liquid delivery device are operable to substantially saturate the working gas.
 35. The system of claim 33 wherein the compressor and vaporizable liquid delivery device are operable to fully saturate the working gas.
 36. An open-cycle gas turbine system for cooling, the system comprising: a compressor having a vaporizable liquid delivery device, the compressor operable to receive a working gas and produce a compressed working gas; a recuperator fluidly coupled to the compressor for receiving the compressed working gas and providing thermal energy to the compressed working gas to produce heated, compressed working gas; a combustion chamber fluidly coupled to the recuperator for receiving the heated, compressed working gas and combusting the heated, compressed working gas to produce an exhaust gas; a first expansion turbine fluidly coupled to the combustion chamber for receiving the exhaust gas and expanding the exhaust gas to produce an expanded exhaust gas and energy; wherein the recuperator is fluidly coupled to the first expansion turbine for receiving the expanded exhaust gas from the first expansion turbine and removing thermal energy to produce a cooled, expanded exhaust gas; a cooler-condenser fluidly coupled to the recuperator for receiving the cooled, expanded exhaust gas and producing a dried working gas; a second expansion turbine fluidly coupled to the cooler-condenser for receiving the dried working gas and producing a cold working gas; and a low temperature heat exchanger fluidly coupled to the second expansion turbine for receiving the cold working gas and delivering thermal energy to the cold working gas.
 37. The system of claim 36 wherein the vaporizable liquid delivery device and the compressor fully saturate the working gas.
 38. The system of claim 36 wherein the vaporizable liquid delivery device and the compressor substantially saturate the working gas.
 39. The system of claim 36 wherein the low temperature heat exchanger is operable to receive a liquefiable gas and to produce a liquid from the liquefiable gas.
 40. The system of claim 36 wherein the cooler-condenser is operable to condense out a condensed liquid from the cooled, expanded exhaust gas and further comprising a conduit fluidly coupled to the cooler-condenser and fluidly coupled to the vaporizable liquid delivery device for delivering the condensed liquid to the vaporizable liquid delivery device.
 41. An open-cycle gas turbine system, the system comprising: a first compressor for receiving a working gas, the first compressor having a vaporizable liquid delivery device and operable to produce a compressed working gas; a cooler-condenser fluidly coupled to the first compressor for receiving the compressed working gas and cooling the compressed working gas to produce a condensed liquid and a cooled, compressed working gas; a conduit for delivering the condensed liquid from the cooler-condenser to the vaporizable liquid delivery device; a second compressor fluidly coupled to the cooler-condenser for receiving the cooled compressed working gas and operable to produce a twice-compressed working gas; a heating unit fluidly coupled to the second compressor for receiving the twice-compressed working gas and providing thermal energy to the twice-compressed working gas to produce an exhaust gas; and an expansion turbine fluidly coupled to the heating unit for receiving the exhaust gas and operable to expand the exhaust gas to develop energy and produce an expanded exhaust gas.
 42. The system of claim 41 wherein the heating unit comprises a combustion chamber.
 43. The system of claim 41 wherein the heating unit comprises a high-temperature heat exchanger.
 44. The system of claim 41 further comprising a conduit fluidly coupled to the cooler-condenser for receiving the condensed liquid and fluidly coupled to the vaporizable liquid delivery device.
 45. The system of claim 41 wherein the vaporizable liquid delivery device and the compressor fully saturate the working gas.
 46. The system of claim 41 wherein the vaporizable liquid delivery device and the compressor substantially saturate the working gas. 